gvi pez maya quarterly report january- march 2010

8/9/2019 GVI Pez Maya Quarterly Report January- March 2010

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Global Vision International,2010 Report Series No. 001

GVI Mexico

Pez Maya, Sian Kaan Biosphere Reserve

Quaterly Report 101

January March 2010


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GVI Mexico Pez Maya Expedition Report 101

Submitted in whole to

GVIAmigos de Sian Kaan

Comisin Nacional de reas Naturales Protegidas (CONANP)

Produced by

Lluvia Iyanu Soto Jimnez Base Manager

Nicola Taylor Field StaffJaen Nieto Amat Field Staff

Stuart Fulton Field StaffSamuel Hope Field Staff

Edward Houlcroft Field Staff

And

Jessica Reimer Scholar Ryan McCartney Volunteer

Katie McHugh Scholar Chloe Juyon Volunteer

Charles Duckworth Volunteer Mark Eakin VolunteerSally OBrien Volunteer Thomas Morgan Volunteer

Laura Sharp Volunteer Emelie Haetner Volunteer

Alessandro Buticcelli Volunteer Charles Crouzieres Volunteer

Sam Handley Volunteer Susan Maclennan Volunteer

Daniel Adams Volunteer Ben Chambers Volunteer r

Tegan Freeburn Volunteer Courtney Schudel Volunteer

Nichola Turpin Volunteer Nicholas Rielly Volunteer

Kathryn Callahan Volunteer Patricia Browne VolunteerJohn Bathgate Volunteer Kristian Volunteer

Jay Gree Volunteer Maja Karlsson VolunteerErika de la VegaSandoval Volunteer

Octavio CoronaOchoa Volunteer

Edited byDaniel Ponce-Taylor

GVI Mexico Pez Maya Programme

Address: Apartado Postal 16, Col Centro, 77710Playa del Carmen, Quintana Roo

MexicoEmail: [email protected]

Web page: http://www.gvi.co.uk and http://www.gviworld.com


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GVI 2010 i

Executive Summary

The twenty seventh 10 week phase of GVI Mexico Pez Maya expedition has now been

completed. During the phase we continued work towards our primary aims of gatheringimportant scientific data on the status of the Mesoamerican Barrier Reef within the Sian

Kaan Biosphere Reserve, working with our local partners and building on our relations

with the local community by offering English and environmental education lessons. The

following projects have been run during Phase 101:

Continuation of the MBRS Synoptic Monitoring Programme (SMP) for the strategic

sites within the northern Sian Kaan Biosphere, providing regional decision makers with

up-to-date information on the ecological condition of the reef

Daily bird monitoring

Incidental sightings programme

Continuation of weekly beach cleans within the reserve, monitoring waste composition

and trends

English language and environmental education classes to the children of Punta Allen

PADI Open Water Diver training for local CONANP rangers

Continuation of the National Scholarship Programme at Pez Maya, whereby GVI Pez

Maya accepts Mexican nationals on a scholarship basis into the expedition


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GVI 2010 ii

Table of Contents

Executive Summary .........................................................................................................i

Table of Contents ............................................................................................................ii

Abbreviations.................................................................................................................iiiList of Figures ................................................................................................................iiiList of Tables ..................................................................................................................v

1. Introduction..............................................................................................................62. Synoptic Monitoring Programme.............................................................................. 7

2.1 Fish Results & Discussion.................................................................................92.1.1 Adult Fish ................................................................................................9

2.1.2 Juveniles ................................................................................................182.2 Coral Monitoring Results ................................................................................21

2.2.1 Benthic Cover ........................................................................................212.2.2 Coral Health........................................................................................... 28

2.2.3 Discussion..............................................................................................313. Incidental Sightings Programme.............................................................................35

3.1 Introduction ....................................................................................................353.2 Methodology...................................................................................................353.3 Results............................................................................................................35

3.4 Discussion ......................................................................................................404. Beach Waste Monitoring Programme ........................................................................42

4.1 Objectives.......................................................................................................424.2 Methodology...................................................................................................42

4.3 Results............................................................................................................424.4 Discussion ......................................................................................................45

5. Bird Survey Programme ............................................................................................485.1 Aims...............................................................................................................48

5.2 Background.....................................................................................................485.3 Methodology...................................................................................................49

5.4 Results............................................................................................................505.5 Discussion ......................................................................................................53

5.6 Limitations and error.......................................................................................545.7 Future work ....................................................................................................55

6. Community Work......................................................................................................567. References.................................................................................................................58


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iv

Figure 2-18 Diversity of corals recorded on CC transects by site in 101.

Figure 2-19 Coral Diversity in 101 by site from coral rover data.

Figure 2-20 Presence of Predation on Corals by Year: S Sponge, F Fish, FW Fireworm, TTunicate, Z Zoanthid.

Figure 2-21 Presence of Disease on Corals by Year: BBD Black Band Disease, DS DarkSpot Disease, WBD White Band Disease, YBD Yellow Blotch Disease, RBD Red BandDisease, WP White Plague, HP Hyperplasm, NP Neoplasm, Other.

Figure 2-22 Presence of Bleaching on Corals by Year: BL Full Bleach, P Pale Bleaching,

PB Partial Bleaching

Figure 3-1. Comparison of frequency of groups from 051 to 101..Figure 3-2. Total sightings of sharks, rays and eels from phase 052 to 101.

Figure 3-3. Recorded sightings of individual Ray species from 051 to 101.

Figure 3-4. Recorded sightings of individual Shark species from 051 to 101.

Figure 3-5. Total of sightings of individual turtle species by phase.

Figure 3-6. Total sightings of individual Mammal species by phase.

Figure 3-7. Lionfish.

Figure 4-1. Litter collected during 101. Numbers show actual mass collected (kg).

Figure 4-2. Total weight of rubbish collected (kg) from 052 to 101 (all litter collected).

Figure 4-3. Percentage make up of each category from 052 to 101 (total litter collected).

Figure 4-4.Total litter collected during the first six transects of each phase since 2007 (forstandardised comparison). Phase 101 collected considerably less rubbish than previousphases.

Figure 5-1. Composition of total bird sightings in 101 (Others refer to species presenting

a percentage of 1% or less).

Figure 5-2. Most commonly recorded species (more than 50) in 101 compared to 091.

Figure 5-3. Bird sightings by status.


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v

List of Tables

Table 2-1. Name, depth and GPS points of the permanent (SMP) monitoring sites for the

GVI Pez Maya programme during phases 2 and 4.

Table 2.2. Fish species diversity per site monitored in 101.

Table 2-3. Sizing Validation: undersizing of fish in data collected at PL20 and PX05.


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GVI 2010 Page 6

1. Introduction

The Mesoamerican Barrier Reef System (MBRS) extends from Isla Contoy at the North of

the Yucatan Peninsula, Mexico, to the Bay Islands of Honduras through Belize and

Guatemala and is the second largest barrier reef in the world.

The GVI Marine Programme was initiated within Mexico with the set up of its first base,

Pez Maya, in the Sian Kaan Biosphere Reserve in 2003. Since then the programme has

flourished, with a sister site being set up in the south of Quintana Roo at Punta Gruesa.

The current project at GVI Pez Maya is assisting Amigos de Sian Kaan (ASK) and

Comisin Nacional de reas Naturales Protegidas (CONANP) to obtain baseline data for

the reefs of the north Sian Kaan by conducting marine surveys, to ascertain areas of high

species diversity, areas of high algal mass, fish species and abundance amongst other

reef health indicators. Using this data, ASK and its partners can begin to focus on the

areas needing immediate environmental regulation, implementing management protection

plans as and when required. Surveys using the same methodology are being conducted

by a number of bodies through the entire Mesoamerican Barrier Reef, in Belize, Honduras

and Guatemala, coordinated by the MBRS project group.

With the continuing development of the Riviera Maya, effective monitoring is becoming

evermore important. Inadvertent environmental degradation can be prevented if the

appropriate measures are taken to advocate long-term, sustainable ecotourism. Continual

assessment of Sian Kaans reef health can support and develop management strategies

for the area, the work outlined in this report forming a key part of that assessment.

This report will focus primarily on diversity of both fish and coral, analysis of fish and algal

assemblages, coral health and seasonal trends. The report also summarises the other

work completed this phase in GVI Pez Mayas science and community projects.


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GVI 2010 Page 7

2. Synoptic Monitoring Programme

The monitoring program that takes place every expedition at Pez Maya replicates a similar

study conducted over 15 years ago (Padilla et al. 1992), concentrating monitoring effortson the reefs in the northern area of the Sian Kaan Biosphere. The current project run by

GVI uses similar methods implemented during this earlier study (Almada-Villela et al.,

2003 and Woods-Ballard et al. 2005). Table 2-1 details the name, depth and GPS points

of the monitoring sites with Figure 2-1 showing the locations of the monitoring sites on a

map of the surrounding area.

Table 2-1. Name, depth and GPS points of the permanent (SMP) monitoring sites for the GVI Pez Mayaprogramme during phases 1 and 3.

Location Site IDDepth

(m) Latitude Longitude

LC10 10.9 19.78693 N 087.43310 WLa ColoniaLC20 17.9 19.78637 N 087.42628 WPJ05 6.1 20.01498 N 087.46475 W

Paso JuanaPJ10 9.1 20.01690 N 087.46215 WPL05 3 20.05045 N 087.47035 WPL10 6.7 20.05200 N 087.46625 WPaso LagrimasPL20 16.7 20.05138 N 087.46275 WPX05 7.4 19.93205 N 087.43415 WPX10 12.3 19.93395 N 087.43355 WPunta Xamach

PX20 16.2 19.93333 N 087.43213 W

These GPS points are in the WGS84 datum, rather than the NAD27 Mexico datum, for use

with GIS software and further reporting.

For more information regarding SMP methodology and training, please refer to Global

Vision Internationals Annual Report 2006, available online at http://www.gvi.co.uk


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GVI 2010 Page 8

Figure 2-1. Map of the permanent monitoring sites for GVI Pez Maya (Courtesy of JuniperGIS).


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GVI 2010 Page 9

2.1 Fish Results & Discussion

2.1.1 Adult Fish

101 phase saw 64 monitoring transects carried out at eight sites (eight transects per site)

in the vicinity of Pez Maya, PJ05, PJ10, PL05, PL10, PL20, PX05, PX10 and PX20. Each

monitoring site that was begun was completed, with a total of 628 adult fish belonging to

12 families identified. An average of 17 fish per transect were recorded, but the abundanceof fish varied from site to site (standard deviation: 7), being less abundant in shallow

sites (5m). The 10m sites were the ones with higher abundance of fish, followed by the

20m sites (Figure 2-2).

0

5

10

15

20

25

30

35

40

45

PJ05 PJ10 PL05 PL10 PL20 PX05 PX10 PX20

Monitored sites

Averageofindividualsre

cordedper

transect

Figure 2-2. Average number of species recorded per transect in each monitoring site during 101 phase.

The family presenting highest abundance was Acanthuridae (242 individuals), followed by

Haemulidae (191), Scaridae (44), Lutjanidae (40), Chaetodontidae (35), Pomacentridae

(28) and Serranidae (28) families. The families less represented were Pomacanthidae (8),


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Balistidae (5), Caranjidae (4), Labridae (2) and Monacanthidae (1). No members of

Sphyraenidae family were recorded during 101 phase (Figure 2-3).

0

50

100

150

200

250

300

Acanthu

ridae

Balist

idae

Caran

jidae

Chaetod

ontidae

Haem

ulidae

Labridae

Lutjanid

ae

Monacanth

idae

Poma

canth

idae

Poma

centrida

e

Scaridae

Serra

nidae

Sphyrae

nidae

Family

N

umberofindividuals

Figure 2-3. Individuals recorded in each target family during 101 phase.

Half of the total number of target species was recorded in 101 phase: 34 of 68. Each

family presents a different number of target species but most of them were not

represented by the totality of their members (Figure 2-4): families represented by the

totality of their members were Acanthuridae (3), Caranjidae (1) and Pomacentridae (1).

The ones represented by about half of their members were Chaetodontidae (3 of 5),

Haemulidae (8 of 13), Labridae (1 of 2), Pomacanthidae (3 of 6) and Scaridae (6 of 12).

The ones represented by one third of their members were Lutjanidae (3 of 8),

Monacanthidae (1 of 3) and Serranidae (3 of 8). The least represented family was

Balistidae, having Balistes vetula as the only species recorded (five times) (Figure 2-4).


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GVI 2010 Page 11

0

2

4

6

8

10

12

14

A

canth

urida

e

Balistid

ae

Caranjida

e

Chaetod

ontid

ae

Haem

ulida

e

Labrida

e

Lutja

nidae

Mona

canth

idae

Pom

acan

thida

e

Poma

centrid

ae

Scarida

e

Serra

nidae

Sph

yraen

idae

Family

Numberofspec

ies

Recorded species in 101

Target species

Figure 2-4. Number of species per family recorded in 101 and total number of target species per family.

Looking at the abundance of species recorded per family and per site it can be seen that

not only the abundance of species recorded varies from family to family but also from site

to site (Figure 2-5 and Table 2.2).


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GVI 2010 Page 12

Figure 2-5. Number of species recorded per family and per site during 101 phase

The monitoring sites presenting a highest diversity are PJ05 (8.58), PL20 (8.26) and PJ10

(8.15) and the ones with the lowest one are PX05 (2.67) and PL05 (3.45). The low

diversity observed at PX05 seems to match the coral data, which is also low (3.20)

compared with other sites like PL20 the diversity in coral communities is the highest (8.24)

(Table 2-2).


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GVI 2010 Page 13

Table 2-2: Fish species diversity per site monitored in 101

SiteNumber ofindividuals

Number ofspecies

Number offamilies

Simpson Dindex

PJ05 72 19 8 8.58PJ10 107 20 8 8.15PL05 71 12 6 3.45PL10 103 17 6 7.31PL20 89 19 9 8.26PX05 4 3 3 2.67PX10 116 17 9 5.49

PX20 66 15 8 4.69

Across all sites, the most common species wasAcanthurus bahianus, accounting for 25%

of all fish identified on the transects (Figure 2.6). Other common target species (with an

abundance of 5% or more) were Acanthurus coeruleus (13%), Haemulon flavolineatum

(11%), Haemulon plumieri (8%), Pomacanthus arcuatus (5.7%) and Haemulon sciurus

(5%) (Figure 2-6).


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GVI 2010 Page 14

Figure 2-6: Total number of individuals recorded in each family during 101 phase.

Comparison between PX05 and PL20

Since PX05 is the sight presenting the lowest diversity and PL20 the highest in both, fishand coral community, data from PX05 and PL20 were compared with results from the

January phase back to 2006, to examine any spatial differences occurring between the

sites.

PX05 is located 9.19km south of Pez Maya, whilst PL20 is located 5.5km north of Pez

Maya. The sites vary greatly in respect to topography. PX05 is a shallow (7m) site located

relatively close to the shore and is typified by low coral and fish abundance over a patch

reef. PL20 is located at the deeper end (18m) of a spur and groove reef where the reefmeets the sand. It is high in fish and coral abundance.

Only 3 species were identified at PX05 (Figure 2-5);Acanthurus chirurgus, Balistes vetula

and Ephinephelus guttatus. Previous phases have recorded similar species, almost always

in low numbers, except forAcanthurus bahianus being recorded 21 times in 071. At PL20,


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19 species were recorded in 101 (Figure 2-5), 18 in 081, and 21 in 071. A wider range of

species were also recorded, ranging from grazers such as the Acanthuridae spp. to

predators such as Caranx ruberand Bodianus rufus.

As way of comparison the trophic levels of the fish were calculated and plotted in Figure 2-

7. Trophic levels were calculated from Froese & Pauly (2006). Figures 2-8 and 2-9 shows

the average trophic levels of the fish at each site. PX05, despite having fewer fish has a

higher average trophic level due to the presence of individual predators, likely searching

for food in the barren area. PL20, due to its higher abundance of fish provides an average

that is less affected by individual species. Since 071 there has been a slight decline in

trophic level of the identified fish. Further studies should continue this study to try to clarify

whether there is a further decline over time. A decline in trophic level is symptomatic of

fishing pressure. A larger sample size is also needed to smooth out anomalies caused by

chance sightings of high trophic level fish.

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

061 071 081 101

Phase

Trophic

Level

PX05

PL20

Figure 2-7. Trophic Level changes since 2006


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0

5

10

15

20

25

30

2 2,5 3 3,5 4 4,5

Trophic Level

061

071

081

101

Figure 2-8. Trophic Categories at PX05

Figure 2-9. Trophic Categories at PL20

Both PX05 and PL20 have more fish located at the lower trophic levels than higher ones

(Figures 2-8 and 2-9). Studies of pristine, healthy reefs have shown that marine reef

ecosystems are top heavy with an abundance of predators keeping a rapidly turning-over

population of prey in check. Very few ecosystems exist in this state at the present time.

PL20 reef environment is high in coral and fish abundance, however the majority of the

fish surveyed are found in the bottom trophic level. At the higher trophic levels the

abundances are low.

0

10

20

30

40

50

60

70

2 2,5 3 3,5 4 4,5

Trophic Level

061

071

081

101


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The amplitude of the trophic level recorded in each phase is often dependent on the

presence of school of high trophic level fish passing through one of the eight transects.

Although the methodology applied to the monitoring is thought to be representative of the

state of the reef, in this case, it is probable that a larger sample size would help to smooth

individual variations, highlighting whether schools are more common on one phase than

another and that it is not only due to chance.

Fish sizing was examined at PL20 and PX05 to attempt to analyse the accuracy of fish

sizing undertaken by the volunteers (Table 2-3). In Table 2-3 fish have been classified as

undersized if they are below the average size range of adults commonly seen in that

species. Some error will occur due to the natural variations in intra-specific fish sizes.

The nature of the monitoring programme makes in-water verification relatively difficult due

to logistical and the in-water view point. During recent phases (post-094) steps have been

taken to increase the accuracy of fish sizing due to concerns that many fish were being

sized wrongly. The most common mistakes were undersizing and confusion between

juvenile, intermediate and adult stages in fish with no or little dimorphism between life

stages.

Table 2-3. Sizing Validation: undersizing of fish in data collected at PL20 and PX05

PL20 PX05

Phase

% catergories

withundersizedfish

% of

catergorieswith >50%undersized

fish Phase

% catergories

withundersizedfish

% of

catergorieswith >50%undersized

fish

61 21% 7% 61 50% 50%71 19% 0% 71 25% 12.5%81 22% 16% 81 0% 0%

101 0.55% 0% 101 0% 0%The steps to improve sizing accuracy included:

- Increased number of dives dedicated to fish sizing

- Increased use of in-water measuring aids (such as wooden practice fish and a

ruller)

- More in-depth briefings and tutorials


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The results show a considerable decrease in undersized fish being identified during Phase

101, the first phase with improved teaching recorded in Table 2-3. Similarly, at PL20, the

site with a much higher abundance, there is only a 3% difference in the percentage of fish

being undersized (19-22%).

Further analysis of data from phases since the improved sizing teaching was implemented

will be required to confidently say whether the improvements are effective over a long

period. A possible constraint on the results are that volunteers begin to know the expected

size range of the fish they see and record the fish in to the expected category, not the

actual size. This can only be verified by in-water assessment.

2.1.2 Juveniles

As opposed to previous GVI Pez Maya science reports, this section will not focus as much

on specific juvenile species, but rather temporal changes between seasons. Figure 2-10

compares summer and winter differences in abundance between sites with winter being

the phase 01 (January-March) and summer being the phase 03 (July-September) of the

same year.

0

20

40

60

80

100

120

140

160

180

winter 07 summer 07 winter 08 summer 08 winter 09 summer 09 winter 10

Abundance

PJ05

PJ10

PL10

PX10

PX20

Figure 2-10. Juvenile Abundance per site

Although there are data gaps, some conclusions can be drawn. At the 20m (PX20) site,

there are considerably higher abundances of juveniles in summer than there are in winter.


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This temporal difference is less at PJ10, PL10 but similar for PX10 and, for 5m site (PJ05),

there is little difference between the winter and summer abundances. Overall this suggests

that the juveniles might occupy the shallower sites throughout the year, whilst only venture

to the deeper areas during the summer. Figure 9 does not however reflect the species

composition of the juveniles present. Previous GVI studies have shown that distinct

breeding periods exist for the more common species. In a similar fashion to the adult

section, PX05 and PL20 were compared in respect to the abundance of juveniles at each

site (Figure 2-11).

Figure 2-11. Juvenile species abundance at PX05 and PL20

There are marked species differences between the sites PX05 and PL20. Not only is there

a depth difference, there is also a considerable spatial and topographical difference as

PX05

0

5

10

15

20

25

30

35

40

071 081 101

Phase

Abundance

PL20

0

5

10

15

20

25

30

35

40

071 081 101

Phase

Abundance

Acanthurus bahianus

Halichoeres maculipinna

Thalassoma bifasciatum

Stegastes partitus

Acanthurus coeruleus

Sparisoma aurofrenatum

Halichoeres garnoti


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GVI 2010 Page 20

discussed above. Figure 10 shows the data collected for the winter phase as this was the

fuller data set. As discussed above the summer/winter abundances of juvenile are

generally more varied at the deeper sites, so Figure 10 will record fewer individuals than

there would be in summer at PL20.

No Acanthurus bahianus were identified at the deeper site and A.coeruleus was only seen

in 071, whereas both species were seen every phase (except A. bahianus in 071) at PX05.

Of the Labridae species, Thalassoma bifasciatum was seen regularly at both sites, with a

slightly higher occurrence at PX05. Halichoeres garnoti however, was seen only seen at

PL20, indicating the species preference for reefs with higher coral cover and/or deeper

sights.

Herbivory

As discussed in previous GVI Reports there has been considerable correlation between

the two species (Figure 2-12). particularly since Phase 073, peaks in Acanthuridae have

corresponded with troughs in turf algae concentrations. In 091 the relationship changed

somewhat with low abundances of fish and algae. However during this phase very little

data was collected and only from one site, which biased the results somewhat. Since that

phase the signs have been encouraging for the health of the reef. Acanthuridae

populations increased during 093 and 094 but turf algae abundance have not risen above

34% cover, remaining low in 101 (30%). Acanthuridae populations did decline however,

presumably because their food supply was reduced.


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GVI 2010 Page 21

Figure 2-12. Relationship between turf algae and Acanthuridae Jan2005-Jan2010

2.2 Coral Monitoring Results

2.2.1 Benthic Cover

The benthic cover is recorded using Point Intercept (PI) transects, which collect data

regarding what species are directly below the transect at regular intervals. This data is

then translated into percentage cover for each species, giving an overview of trends

concerning phase shifts and coral health. Because each site is monitored bi-annually only

the data collected in the first and third phases, which monitor the same sites, are used for

this analysis.

The benthic composition at the sites monitored during the first and third phases of the year

on the Meso American Barier Reef at Pez Maya has remained relatively constant between

2005 and 2010. Over this time, the benthos has been dominated by macro algae, with an

average cover of 63.5% and a range from 52.2% in phase 053 to as much as 76.8% in

phase 071. Corallinales (predominatly coralline algaes) have shown the second highest

percentage cover on the areas of reef monitored, with an average cover of 12.2% and a

range of 7.3% to 22.2% in phase 071 and phase 091, respectively. The third mostdominant group in terms of benthic percentage cover is Hermatypic corals with an average

cover of 7.2% and a range of 5.3% in phase 071 and 10.8% in phase 052. The data

collected between 2005 and 2010 also indicate a decline in the zoanthid cover, with the

lowest percentages recorded in phases 093 and 101 (fig. 2-13)

0

10

20

30

40

50

60

051

053

062

072

074

082

084

092

094

Phase

Percentage

abu

ndance

Acanthuridae

Turf algae


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GVI 2010 Page 22

0.0

20.0

40.0

60.0

80.0

100.0

120.0

051 052 053 054 061 063 071 081 083 091 093 101

Phases

Percentage

ofcover

Tunicate

Rubble

Zoanthid

Sand

Porifera

Macroalgae

Hydroid

Hermatypic coral

Gorgonacea

Corallinales

Corallimorph

Bare rock

Figure 2-13 Percentage of cover of benthic species between 051 and 101.

The transects monitored in phase 093 compared to phase 101 seem to have a similar

benthic composition, with the most common groups represented being Algae and

Hermatypic corals. This pattern is seen throughout the data collected since GVI began,

and is also in line with the wider Caribbean region. The phase shift from coral dominance

to algal dominance is also becoming more apparent within our data.

Below shows the percentage of coral cover over the past two years (figure 2-14). The

data for 2007 and phase 091 are incomplete due to the occurrence of Hurricane Dean and

bad weather, respectively; therefore only 2008, 2009 and 2010 have been used for

comparison. This graph suggests a decline in coral cover for all sites, except PJ10, and

shows the coral cover at its highest at the beginning of 2008.


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GVI 2010 Page 23

0

2

4

6

8

10

12

14

16

18

20

081 083 093 101

Phase

Percentage

cover

PX20

PX10

PL20

PL10

PL05

PJ10

PJ05

Figure 2-14 Comparison of coral cover percentage in 081, 093 and 101.

The algal data from 101 was also compared with that of previous years to establish any

trends (figure 2-15).

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

051 052 053 054 061 063 071 081 083 091 093 101

Phases

Percentage

cover Lobophora sp.

Turf algae

Macroalgae

Halimedacea

Dictyotaceae

Blue-Green Algae

Figure 2-15 Comparison of algae presence between 051 and 101.


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GVI 2010 Page 24

The four main groups of algae monitored (Blue-green algae, Dictyota sp, Halimeda sp and

Lobophora sp), were all recorded during phase 101. All were also present in 093, but the

percentage cover differed somewhat between phases. Increases in Lobophora and

Dictyota populations and decreases in Halimeda and blue-green algae populations are

seen from the previous year. It is hypothesized that Halimeda and Dictyota populations

have an inverse relationship; therefore, a decrease in one will stimulate an increase other.

The grouped classifications (Macroalgae and Turf algae) have both increased over the

year. While overall algal cover remains high, it is possible that the species composition is

changing.

The percentage cover of hermatypic corals has fluctuated since GVI started collecting data

in 2005. Coral cover peaked at the start of 2008 when it reached 10% and has declined to

about 7%, which is the average percentage coral cover (fig. 2-16).

0

2

4

6

8

10

12

061 063 071 081 083 093 101

Coralpercentage

cover

0

10

20

30

40

50

60

70

80

90

Algae

percentage

cover

Coral cover

Macroalgal cover


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Figure 2-16 Coral and Macroalgae percentage cover between 2006 and 2010.

When percentage coral cover was compared with the percentage cover of macroalgae, an

inverse relationship between the two emerged. As the percentage of coral cover

increased, the macroalgae seemed to decrease, and vice versa. As Macroalgae and

Hermatypic corals are the first and third most dominant groups recorded on the

Mesoamerican Barrier Reef at Pez Maya, it might be expected that as one decreases the

other would increase. However, no other group recorded shows such a direct correlation,

despite that there was a general increase in all other benthic communities during 081.

These data indicate that as the macroalgae population decreases the biodiversity

increases; therefore, due to the lack of competition for space and light by algae, the coral

population also increases. This is an important observation, as many coral reefs

throughout the world are being outcompeted by algae and as a result there has been a

decrease in biodiversity. If the data show that there actually is a direct inverse relationship

between coral growth and algal growth, this can be valuable for understanding the

dynamics of the reef ecosystem. The reef can build and increase potential substrate for

other colonising species such as zoanthids, tunicates and gorgonians, increasing potential

habitats and food sources for fish and other reef creatures ultimately increasing

biodiversity. However the fluctuations in the data need to take into account the inherent

errors of the data collection process, such as missing data sets and human error, but the

overall trend shows that the region is relatively stable rather than offering a healthy

increase in diversity or coral cover.

Within the coral cover data, the breakdown of frequency of families gives an idea of which

coral groups are the most commonly seen on the reefs in the area. The graph shows the

data as number of points recorded of each family in a given 6 month period to give an

overall view of the abundance of each (figure 2-17).


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0

20

40

60

80

100

120

140

Acrop

orid

ae

Agariciida

e

Fa

viida

e

Meand

rinida

e

Mussida

e

Milleporida

e

Poritida

e

Side

rastreida

e

Astro

coeniida

e

Pocillop

orida

e

Family

Abundence

101

093

Figure 2-17 Frequency of coral families recorden on CC transects.

Although there are some fluctuations within families between the phases, Agariciidae,

Faviidae, Poritidae and Siderastridae are clearly the dominant families on the monitored

sites, which is also confirmed through the coral rover data collected for each site. The data

indicate that there have been changes in abundance between 093 and 101 with the

Musiidae, Milliporidae, Poritidae, Siderasridae and Astrocoeniidae families increasingwhile the abundance of Agariciidae and Faviidae and Meandriidae families has decreased.

The most common species, however, are strong reef building corals such as Siderastrea

siderea and Diploria sp, which is indicative of a resilient reef with the ability to grow. With

the reef structure in place there will always be substrate for other species to attach to, as

well as affording coastal protection and other ecosystem services.

The diversity of corals recorded just within the 101 phase have been split down into sites

(figure 2-18). The types of reef found at Pez Maya are mainly spur and groove, and

transects are taken from three depths (5, 10 and 20 meters) where possible at each site.

The data below illustrates the diversity of coral species at different depths.


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0

5

10

15

20

PX20 PX10 PJ10 PJ05 PL20 PL10 PL05

Site

Numberofspecies

Figure 2-18 Diversity of corals recorded on CC transects by site in 101.

The graph suggests the coral diversity at different depths is relatively the same. The one

exception is PL20, which appears to have almost double the number of species compared

to other sites. However, the methodology used to collect data may not be completely

representative of the actual number of species that grow on the reef due to the

randomness of where the transect is laid and because only corals larger than 10 cm are

measured.

The data gathered through the Coral Rover (CR) surveys gives a more complete idea of

the diversity of corals at each site, as they involve the record of all species seen within a

given swim pattern and a timescale of 30 minutes. The graph below shows the same

information as the previous graph, but using the coral rover data (figure 2-19).


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0

5

10

15

20

25

30

PX20 PX10 PL20 PL10 PL05 PJ10 PJ05

Site

Numberofspecies

Figure 2-19 Coral Diversity in 101 by site from coral rover data.

This graph shows a correlation of diversity within sites by depth. At all of the sites

monitored during phase 101, the diversity increased with depth. The 20 meter sites had

the most diversity, followed by the 10 meter sites and then the 5 meter sites.

2.2.2 Coral Health

The biodiversity and benthic cover are good indicators of reef health, but the coral

communities (CC) transects also allow for analysis on individual coral health regarding

predation, bleaching and disease.

Predation is normally something fairly rarely seen at the monitoring sites of Pez Maya.

The abundance of food sources in the form of algae discourages predation on corals as

there is little need for predators to source energy this way. The graph below illustrates the

presence of predation found on coral colonies recorded through CC transects (figure 2-

20).


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0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

083 091 093 101

Phase

Abundance

RBD

BBD

WBD

WP

YBD

DS

Figure 2-21 Presence of Disease on Corals by Year: BBD Black Band Disease, DS Dark Spot Disease,

WBD White Band Disease, YBD Yellow Blotch Disease, RBD Red Band Disease, WP White Plague, HP

Hyperplasm, NP Neoplasm, Other.

The abundance of Dark Spot (DS) can partly be contributed to the fact that it is common

on one of the most abundant species on the reef, Siderastrea siderea. It is very rare on

other species, but with Siderastrea occurring all over the reef, and the susceptibility of the

species to DS, the frequency is likely to be high. The remaining diseases occur in varying

abundance, with White Plague or Yellow Blotch Disease being the second most common

diseases. Other diseases occur in low frequencies by comparison.

The bleaching data is also lacking one phase for 2009, but again, the frequency appears

to be following a downward trend (figure 2-22). The most common is the pale bleaching

category, which may again be explained by its relationship with the common Siderastrea

siderea species as with the DS. Many of this species presents pale bleaching, which

appears to be a common characteristic that has little proven negative effect on the

colonies. However, there is the potential that this may be a reason behind the high

frequency of DS on Sideratrea sp as the colony may be weakened by the pale bleaching

and therefore more susceptible to negative influences.


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0%

20%

40%

60%

80%

100%

051 052 053 054 061 063 071 081 083 091 093 101

Phase

Colonies PB

P

BL

Figure 2-22 Presence of Bleaching on Corals by phase: BL Full Bleach, P Pale Bleaching, PB Partial

Bleaching

The categories for bleaching have been redefined over the years, which may have had an

impact on the data, but the general trends show a realistic picture of what is happening

concerning each bleaching type.

Fully bleached colonies have been the least common on the monitoring sites, followed by

partial bleaching, with the most common being pale, which is reflected in the graph. There

is also a pattern of decline in bleaching abundance in general that would suggest theenvironmental factors that contribute to bleaching events have lessened. However, this

could also be attributed to the changes in classification and therefore recording of

bleaching.

2.2.3 Discussion

The data, in general, has shown fairly consistent results, taking into account the inherent

errors found in this type of data collection methodology, and the missing data due to bad

weather and logistical issues of getting to sites.

The overall benthic composition has so far shown little change since GVI began

monitoring. The algas are still dominant, occupying well over 50% and as high as 75% of

the substrate. This is a common feature in the Caribbean since the cover shifted from

coral dominance to algal dominance, following certain events that allowed the algae to


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take over. The increased presence of disease and detrimental environmental factors,

combined with changes in abundance of other species (for example, grazers such as the

Diadema urchin) lead to the opportunity for algae to colonise not only the free space, but

also the skeletons of dead corals. They are far more voracious in growth, and therefore

the slower growing corals are not able to colonise the free space before it is taken over by

algae. Events that may lead to a recovery of coral cover over algae would include an

increase in herbivorous (algae eating) species in order to further control the population.

There is a healthy population of other species existing on the reef such as bryozoans,

zoanthids, tunicates and sponges, all playing an important part in the composition and

productivity of the ecosystem, but are not well represented in the data. Sponges, for

example, are filter feeders and are thought to filter out potentially harmful bacteria and

particles from the water column which may have colonised a coral colony and resulted in

disease. They also erode and consolidate the substrate, forming a less porous base for

other species to occupy, and they provide food and a habitat for cryptic species and

recycle nitrogen from the surrounding water. However, their presence is not seen in the

data, possibly due to their growth forms that result, like many other species, in their not

being found on a transect as frequently as other more highly recorded species.

The dominant coral families have remained the same throughout the data, with

Agariciidae, Faviidae, Poritidae and Siderastridae accounting for more than 70% of the

coral abundance. Within these families, Siderastrea siderea and Agraricia agaricites are

the most common corals found on the reef, which are both strong reef building corals.

The biodiversity data (Point Intercept) offers an idea of the number of different species

found on the reefs. Volunteers learn fifty coral species, most of which are found on the

reef, and therefore the data should include a majority of these species. The Coral

Communities (CC) data is limited because of the methodology of randomly laying the

transect, which may not accurately reflect the amount of corals that appear on the reef.

However, the data for the Coral Rover (CR) should include all species seen in a given

space over a 30 minute period, and therefore all the major species found on the reef

should be included. This is not reflected in the graphs, with the CR graph (figure 2-24)

showing only a slight increase in the number of species found in comparison to the CC


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data. This could be an error of the methodology, as many species are found in certain

locations on the reef, or are cryptic and difficult to see which may result in the biodiversity

appearing less than in reality.

There is little reef fish predation seen on the corals at Pez Maya. However, there is a high

abundance of damselfish and parrotfish, which are the main species that predate on corals

in the region. The Parrotfish scrape algae from the coral tissues, leaving marks and

removing polyps, and the damselfish create a territorial garden where they remove polyps

in order to let turf algae colonise, providing a source of energy for them. However, the

general abundance of algae on the reef lowers the competition for this food source,

meaning the fish can find the resource without damaging corals. The peak of fish

predation in 2008 (081) could be explained by a lack of turf algae in 081, but there is little

data to support this was argument. It could also be an error in data collection, with

misidentification of the predation for a phase that could have led to the peak shown in the

graph.

Sponge overgrowth is the most common predation seen on the reef, generally in the form

ofCliona species. These species form a thin layer over the top of the coral, smothering

the polyps as it progresses. The result is a thin covering over the skeleton, leaving the

corallites visible, with the bulk of the sponge buried in the skeleton. The sponge then

secretes an acid that de-stabilises the skeleton, eroding the mass into sediment which is

then transferred either to the beach, or re-stabilised in cracks and crevices on the

substrate. There is a high presence of this type of sponge on the reef, and with little free

space due to the algae cover, they predate on the live, slow growing coral.

By far the most commonly recorded disease is DS which could be for two reasons; either

the conditions that favour DS are growing stronger, or that the species that are more

susceptible to the disease are the dominant species on the reef. The latter seems to be

the case. The Siderastrea sp. present most with DS, and as stated previously, are one of

the most common species to be found on the reef. The disease does not appear to have a

huge effect on corals other than Siderastrea sp, and is rarely found on other colonies.

Even when found on colonies, it doesn`t appear to have a profound effect on the polyps,


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but may contribute to weakening them and allowing other threats to take hold, such as

other diseases, algae or sedimentation.

The bleaching figures show a decrease in the frequency of bleaching recorded on the reef.

However, there have been some changes made in the way bleaching is taught to the

volunteers which may affect the frequency of colonies being recorded as bleached.

After the increase of bleaching in 2005, which may be attributed to the environmental

conditions of that year due to the El Nio effect, the bleaching figures are stabilising again

and have dropped considerably. The changes made to the classification of bleaching may

become apparent throughout the 2009-2010 data, but even with this in mind, the presence

of bleaching on the reef has been low. The predicted rise in coral bleaching outbreaks for

the end of 2009 have not occurred in 101 as there were no recored incidents of coral

bleaching.

In general, the results are indicating a slight downward trend of threats to coral health, but

with little evidence of coral cover recovery. The algal dominance is continuing, leaving

less space for the slow growers such as corals to regain ground. The prediction for an

increase in bleaching events may result in increased disease presence, as colonies will be

weakened by the loss of zooxanthellae, leaving them open to other threats such as

waterborne bacterias. The continued collection of data should illustrate any changes that

are occurring.


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3. Incidental Sightings Programme

3.1 Introduction

In 2003 GVI Pez Maya implemented a programme to record incidental sightings of

megafauna. This included four general categories: turtles; sharks, rays and eels; marine

mammals, and snakes and crocodiles. In phase 101 this list was expanded to include land

mammals and lionfish, and the shark category has been broken down into individual

species of sharks, rays and eels. These species are not included in the MBRS monitoring

programme that is implemented, but are good indicators of reef health and provide early

warnings of changes, therefore it is useful to continue keeping long term records of which

species are around.

3.2 Methodology

The following information is recorded each time a species on the list is identified where

possible:

Date

Time

Location

Depth

Size

Species

Number

In addition, the current and behaviour is recorded for the lionfish as the data is added to a

larger database for the whole area affected by the invasive species.

3.3 Results

A total of 188 incidental sightings were recorded during 101 which Is the highest of all

phases so far. Eels and rays were the most abundant with eels totalling 64 and rays

totalling 61 sightings. These two groups are the most abundant in almost all phases,

consistently having the highest frequency of sightings. Turtles and marine mammals are

the second most common groups, followed by sharks and snakes and crocodiles as the

least common sightings (figure 3-1). Lionfish totalled at 24 in phases 101 which is the

highest number recorded in a phase to date.


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0

20

40

60

80

100

120

140

160

180

200

51 52 53 54 61 62 63 64 71 72 73 74 81 82 83 84 91 92 93 94 101

Phase

Frequency

Turtles

Snakes and Croc odiles

Sharks

Rays

Marine mammals

Eels

Figure 3-1.Comaparison of frequency of groups from 051 to 101.

The sharks, rays and eels groups encompass two of the most common groups sighted on

the reef at Pez Maya. The rays and eels are in relative equilibrium, both in high numbers

in comparison with the other groups. The shark category however has fewer sightings in

total (figure 3-2). This is could partly be due to the fact that sharks are large predators and

therefore competition results in fewer individuals found on a reef, plus they are mainly

pelagic creatures that do not make their home on the reef. Rays and eels however, live onand around reef areas and therefore are more likely to be sighted more frequently. Figure

3-2 also shows a substantial increase in sightings during phases 101. This is unlikely to

be a true pattern, but rather a result of increased dive numbers and persistent recording of

all incidental sightings.


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GVI 2010 Page 37

0

20

40

60

80

100

120

140

160

51 52 53 54 61 62 63 64 71 72 73 74 81 82 83 84 91 92 93 94 101

Phase

Frequency Sharks

Rays

Eels

Figure 3-2. Total sightings of sharks, rays and eels from phase 052 to 101

Within the ray category, 6 species of rays have now been identified at Pez Maya including

the yellow stingray, spotted eagle ray, southern stingray, lesser electric ray, giant manta

ray and the Caribbean stingray. The southern stingray is by far the most common as

recorded in most phases, however, there is the possibility that misidentification has

occurred as the Caribbean stingray is very similar and has been recorded in recent

phases. The two species together however remain the most common sighted on the

reefs. With a combined total of 46 individuals in 101 (Figure 3-3).

0

10

20

30

40

50

60

70

51 52 53 54 61 62 63 64 71 72 73 74 81 82 83 84 91 92 93 94 101

Phase

Frequency

Yellow Stingray

Unidentified Ray

Spotted Eagle Ray

Southern Stingray

Less er Electric Ray

Giant Manta Ray

Caribbean Stingray

Figure 3-3.Recorded Sightings of Individual Ray Species from 051 to 101

When broken down into categories, the most common shark species is the nurse shark

shown in Figure 3-4 below. The 4 other species that have been sighted are either no


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GVI 2010 Page 38

longer recorded (Blacktip and reef sharks), only recently recorded in low numbers

(Hammerhead) or generally sighted in low numbers (Bull shark). The nurse shark is a reef

dweller and is able to remain in one place without having to move to breathe; therefore

they are the easiest and most likely to be spotted on Pez Maya sites. The remaining

species are all pelagic and mobile, therefore sightings are far more chance than for the

homely nurse shark.

0

2

4

6

8

10

12

14

16

18

20

51 52 53 54 61 62 63 64 71 72 73 74 81 82 83 84 91 92 93 94 101

Phase

Fr

equency

Unidentified shark

Reef Shark

Nurse Shark

Great Hammerhead

Bull Shark

Blacktip Shark

Figure 3-4.Recorded Sightings of Individual Shark Species from 051 to 101

During phase 101 a total of 3 turtle species were recorded, as in all other phases. The

fourth species that can be found in the area, the Leatherback, has not been recorded sincethe program began. Within the total of 21 individuals, 3 were Green, 11 were Hawksbill, a

further 3 Loggerheads and 4 unidentified individuals (Figure 3-5). Sightings have

fluctuated throughout the monitoring period which is mainly due to the quality of data

collection. However, some of the fluctuations may be related to the nesting season

between May to September, which could result in an increase of sightings around these

phases. The numbers in general result in a fairly stable population of turtles in the area,

with a few greater exceptions around the nesting season in 2006 and 2007. In general,

the beginning of the nesting season does see an increase in the number of turtlesrecorded, shown as an increase in the 02 phases of each year.


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0

5

10

15

20

25

30

35

40

45

51 52 53 54 61 62 63 64 71 72 73 74 81 82 83 84 91 92 93 94 101

Phase

Frequency

ofSight

ings

Green

Haw ksbill

Loggerhead

Unidentif ied Turtle

Figure 3-5. Total sightings of individual turtle species by phase

The sightings of marine mammals fluctuate greatly, as they are highly mobile and often

stay further out to sea than we take the boats. Dolphin encounters are generally from the

boat rather than underwater, and are attracted by the engine and motion. Manatees are

curious but cryptic and prefer the calm waters of the mangrove lagoons than the ocean.

According to the chart (figure 3-6), manatee sightings may be decreasing in frequency as

there is no record of them for 3 of the last 4 phases.

0

5

10

15

20

25

51 52 53 54 61 62 63 64 71 72 73 74 81 82 83 84 91 92 93 94 101

Phase

Frequency

Unidentified dolphin

Bottlenos e dolphin

Manatee

Figure 3-6. Total sightings of individual Mammal species by phase The lionfish, pictured below is an invasive species that is plaguing the wider Caribbean.

Its presence will affect the balance and therefore conservationists up and down the coast

are monitoring its movements in order to establish a management plan and track the

spread. It has now become an incidental sighting, with the first phase having a count of


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24. Hopefully the management plans and removal schemes will see a balance, if not a

reduction in the frequency of these sightings.

Figure 3-7. Lionfish.

3.4 Discussion

Incidental sightings of large marine creatures are often good indicators of how healthy an

ecosystem is. As can be seen from the data, the number of sightings and species

recorded varies from phase to phase, with few obvious trends. These species are highly

mobile animals and therefore their movements depend on a range of external factors.

Phase 101 had the greatest total number of recorded incidental sightings since the

implementation of the programme. Over the past year there has been a steady increase in

the number of sightings, suggesting an increase in reef health. However, this could also

be due to better record keeping over the course of the year. Variation in recorded

numbers could also be a reflection of the amount of diving that occured.

It is thought that some categories or species (e.g. snakes) may be under-represented as

observers tend to concentrate on known target species and forget to record other species.

Shark, rays and eels had the largest number of sightings overall, with 142 individuals

recorded. This is also the most number of sightings that have occurred in this category

since the programme has been in effect. Following the trend since phase 074 shows a

steady increase in the number of sightings. In 073, Hurricane Dean hit the coast of Mexico

and greatly affected the reef and animals that live in and around it. The incidental


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sightings recorded during 101 shows a return to similar numbers before the hurricane hit,

suggesting reef recovery.

Marine mammal sightings have been increasing in the last three phases, and are back

amongst the totals recorded in the most frequent phases. All mammals seen were

dolphins, and although some are unidentified, it is likely that they were all bottlenose as

these are the main species seen in the area.

The number of turtle sightings has increased to that of the first phases of 2009 after a drop

in 094. This could be due to the proximity of the turtle season, or possibly a lapse in

records for the previous phase.

In general, sightings are on the increase, which not only indicates an improvement of the

quality of data collection and recording, but also an increase in sightings which is a good

indicator if reef health in the area.


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4. Beach Waste Monitoring Programme

4.1 Objectives

1. Collect data that quantifies the extent of marine litter.

2. Conserve terrestrial and marine fauna threatened by litter.

3. Improve of beach aesthetics.

4. Create and use of methodology suitable for continuing in future expeditions.

5. Create a monitoring programme that can be implemented in other locations within

the reserve.

4.2 Methodology

The beach clean takes place weekly along the same 300 metre stretch of beach. The

beach transect is cleaned one week prior to the beginning of data collection so that only

the weekly accumulation of marine debris is recorded. Marine debris is collected from the

tidemark to the vegetation line to eliminate waste created by inland sources. The waste is

sorted into categories, then weighed and recorded by category. The litter is categorised as

follows:

o Fabrics o Natural materials

o Glass o Medical waste

o Plastics o Rubber

o Polystyrene o Rope

o Metals o Other

4.3Results

A total of nine beach cleans were carried out this phase between January 16 and March13, 2010. The majority of litter mass collected was made up of plastics (65.64 kg) followed

by natural materials (11.46 kg), other (9.98 kg), glass (5.10 kg), rope (4.61 kg),

polystyrene (2.81 kg), metals (0.31 kg), and medical waste (0.09 kg) (Figure 4-1). Fabric

and rubber did not wash up on the transect this phase and therefore were not collected. A


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total of 99.50 kg of litter was collected over all nine cleans. This is a fairly large reduction

from the previous phase (Figure 4-2).

65,64

9,98

11,46

0,090,31

5,104,612,81

Glass

Medical Waste

Metals

Natural Material

Other

Plastic

Polystyrene

Rope

Figure 4-1.Litter collected during 101. Numbers show actual mass collected (kg).

0

50

100

150

200

250

052

053

054

061

063

064

071

072

073

074

081

082

083

084

091

092

093

094

101

Phase

Totalweightofmarinelitter

(kg)

Figure 4-2. Total weight of rubbish collected (kg) from 052 to 101 (all litter collected).


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The composition of all litter collected across phases aside from 064 indicates that plastic is

consistently the largest contributor to the total weight of litter collected (31-78% of total),

with 073 having the highest percentage of plastic (78.16%) (Figure 4-3). Phase 101

follows this trend. Other categories vary widely between phases, with no obvious trends.

0%

20%

40%

60%

80%

100%

05205305

406

106306

407

107207307

408

108208

308

409

109209309

4101

Phase

CompositionofWaste

Rubber

Rope

Polystyrene

Plastic

Other

Natural Material

Metal

Medical Waste

Glass

Fabric

Figure 4-3. Percentage make up of each category from 052 to 101 (total litter collected).

0

20

40

60

80

100

120

140

160

180

200

071 072 074 081 082 083 084 091 092 093 094 101

Phase

Adjustedtotalweightoflitter

collected(kg)

Figure 4-4. Total litter collected during the first six transects of each phase since 2007 (forstandardised comparison). Phase 101 collected considerably less rubbish than previous phases.


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The first six litter collections of each phase were totalled to gain a standardised view of the

amount of data that is collected (figure 4-4). As shown, phase 101 collected considerably

less rubbish than previous phases in the first six weeks, possibly due to unusually calm

weather in the region.

4.4 Discussion

The beach along Pez Maya directly faces the Caribbean current, which originates from the

equatorial Atlantic Ocean and transports significant amounts of water north-westwards

through the Caribbean Sea and into the Gulf of Mexico via the Yucatan current (Gyory,

2006). These currents may act to drive litter from far a field towards the shores of the

Yucatan. This is further compounded by boat traffic in the Caribbean and outflows from

rivers, storm drains and other anthropogenic sources. It is therefore likely that weather

changes affecting sea turbulence and tide-lines will affect the amount of marine debris

being washed up. During 101 the weather at Pez Maya was fairly calm, which may explain

why so little rubbish was collected on the beach.

As can be seen in figures 4-1 and 4-3 plastic dominates the collection across almost all

phases, except for 064. This is likely to be because plastic is generated in large quantities

by humans, remains in the environment for long periods of time and is very light.

Therefore plastic is able to be carried over many miles and deposited far from its source.

Heavier items such as metals are not as abundant in beach litter because they are likely to

sink before reaching the shore.

Plastic is probably the most damaging litter category that we monitor. This is due to the

fact that it can absorb and release poisons into the environment and because it persists in

the environment for many years. Plastic does not fully decompose; instead it breaks down

into small particles resembling plankton which are frequently ingested by marine creatures

and birds. Plastics can also entangle and suffocate wildlife.

The comparative results of litter composition between phases at Pez Maya show some

variation (figure 4-3). The methodology for the beach cleans has changed slightly over the

years, which can account for some of the differences. For example, prior to 2006 the data


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was recorded as specific items collected, rather than grouping the items into categories.

During phase 061 the fabric, medical waste and other categories were not used and in 063

the rope and plastic categories were combined. The number of collections carried out also

varies between phases, possibly because of bad weather or commitments made by GVI,

such as community work, which occasionally cause one or more weeks to be missed. For

example in 073 only four collections were carried out and no data was collected for 062.

For this reason, Figure 4-4 only takes into account the first 6 collections in each phase to

give a more accurate reflection of litter collected without differences introduced by different

collection efforts.

In 092 a new initiative was implemented which involved cleaning the area along the length

of the shore from the bridge to the point south of Pez Maya in an attempt to improve the

aesthetics of the beach and reduce the litter prior to the beginning of the main nesting

season for turtles and birds. This collection was not quantified and was expected to impact

the data as it would reduce the amount of litter arriving in the transect area by longshore

drift. This could account for some of the reduction seen in phase 101 from the same phase

of previous years. In the two phases prior to beginning to clean this area, the amount of

litter collected increased. This may indicate that the majority of the litter is not transported

into the transect by longshore drift, or that the effects of weather on the amount of litter

washed up are more important than those of longshore drift. It will therefore be more

interesting to compare phases at the same time of year to examine the effects of

longshore drift on litter deposition at Pez Maya.

Although efforts are made to collect only marine debris, it is clear that not all litter is

washed ashore and that part of it, as yet unquantified, comes from recreational activities

and people visiting the beach. It was thought that rubbish bins placed at the bridge in 082

may have reduced litter, accounting for some of the apparent decrease in the following

phases in comparison to previous years. However many of these bins have since been

removed or destroyed so it is not possible to be sure if subsequent collections are a result

of marine debris or local waste. The rubbish bins did require emptying frequently, which is

a good sign that people will responsibly dispose of their rubbish if given the facilities to do

so. Signs encouraging people to keep the lagoon and beach clean have been put up on


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and around the bridge to continue to remind visitors of the impact rubbish can have on the

environment.

Although in many countries efforts are being made to reduce the amount of plastic and

other wastes that humans use, oceans do not respect national boundaries and litter may

wash up on shore having been carried from one country to another. With the amount of

waste that can remain in oceanic currents for years without sinking or biodegrading, it is

likely that a reduction in the amount of waste produced now will not be noticed along our

shorelines for many years.


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5. Bird Survey Programme

GVI Pez Maya initiated a birding project in January 2006. This has been continued and

developed by volunteers and staff of the MBRS reef monitoring project based at Pez

Maya.

5.1 Aims

The aims of the bird project are to:

Develop a comprehensive species list for the area.

Gain an idea of the abundance and diversity of bird species. Long-term bird data

gathered over a sustained period could highlight trends not noticeable to short-term

surveys and could support some of the other, more detailed, bird studies being

conducted in the Sian Kaan reserve.

Educate the volunteers in bird identification techniques, expanding on their general

identification skills. The birding project also provides a good opportunity to obtain a

better understanding of area diversity and the ecosystem as a whole.

Consider the overall success of the project and consider possible means for its

future development.

5.2 Background

With regard to avi-fauna, Mexico, Central and South America can be divided into three

distinct regions separated by mountain ranges: the Pacific slope, the Interior and the

Atlantic slope. These regions can be further divided into other sub-zones, based on a

variety of habitats.

The Yucatan Peninsula lies on the Atlantic slope and is geographically very different fromthe rest of Mexico: a low-level limestone shelf on the east coast extending north into the

Caribbean. The vegetation ranges from rainforest in the south to arid scrub environments

in the north. The coastlines are predominantly sandy beaches but also include extensive

networks of mangroves and lagoons, providing a wide variety of habitats capable of

supporting large resident populations of birds.


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Due to the location of the Yucatan peninsula, its population of resident breeders is

significantly enlarged by seasonal migrants. There are four different types of migratory

birds: Winter visitors migrate south from North America during the winter, from August to

May. Summer residents live and breed in Mexico but migrate to South America for the

winter months. Transient migrants are birds that breed in North America and migrate to

South America in the winter but stop or pass through Mexico. Pelagic visitors are birds that

live offshore but stop or pass through the region.

Pez Maya is located in the Sian Kaan Biosphere Reserve (SKBR) on a narrow peninsula

southeast of Tulum between a large network of mangrove lagoons and the Caribbean Sea.

SKBR contains three key ecosystems; marine environment, wetland and forest. The

reserve is thought to contain 372 bird species (Mackinnin, 2005).

5.3 Methodology

Bird monitoring surveys are conducted using simple methods based on the methodology

of GVI Costa Ricas bird monitoring program. Groups of two volunteers accompanied by a

member of staff monitor for 30 to 40 minutes each morning, along one of the five

predefined transects. These transects were selected to cover a range of habitats, including

coastline, mangroves, lagoon, littoral forest, secondary growth and scrub. To reduce

duplication of data, recordings are taken in one direction only, attempting to avoid double-

counting. In some cases where, a large flock was observed, numbers could only be

estimated.

Species are identified to the highest taxonomic level possible according to the time the

recorder has to properly recognise the key features and their experience. Inexperienced

birders learn to identify birds in the field by describing the birds to one another and using

field guides and binoculars. Visual identification is used, although easily recognisable and

distinct calls may also be used where an experienced recorder is certain of species and

number.


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Every survey records the following information: location, date, start time, end time,

volunteers and number of each species seen. Wind and cloud cover are also recorded to

allow consideration of physical parameters. Cloud cover is estimated as in the reef

surveying programme, whereas wind strength is estimated and assigned a number, based

on the criteria of the Beaufort scale. The data is entered into Microsoft Excel for analysis.

5.4 Results

40 transects were carried out this phase, 8 transects at each site. Each transect lasted an

average of 33 minutes (range 23 - 48 minutes) and was conducted by between 1 and 4

observers. A total of 1682 individuals were recorded, 1505 of which were identified to

species level and 177 to genus level.

Figure 5-1 shows the percentage of the species of birds observed in 101. The group

Others regroup the less common species, with a percentage of 1 % or less. It can be

seen that the most commonly counted species was the Royal Turn with 278 sightings,

followed by the White Winged Dove (202 sightings), the Magnificient Frigattebird (148

sightings), the Great Tailed Grackael (130 sightings), Ruddy Turnstone (127 sightings) and

the Brown Pelican (104 sightings).


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Figure 5-1. Composition of total bird sightings in 101 (Others refer to species presenting a

percentage of 1% or less).

Figure 5-2 shows the most commonly recorded species (more than 50 individuals in anyphase) in 101 phase and in the same phase of the previous year (091). The Royal Tern

was the most frequently recorded species in both years, showing higher numbers (two

times more) in 101 phase (278) than in 091(182). The White Winged Dove and the White

Ibis showed as well two times more individuals in 101 (202 and 57 respectively) than in

091 (89 and 31 respectively). The species that showed more different results from one

phase to the other was the Great Blue Heron, being six times more abundant in 101 than

in 091 phases. The species that were more abundant in 091 were the Sanderling (161 in

091 and 37 in 101) and the Turkey Vulture (58 in 091and 27 in 101). All the other speciespresent similar numbers between both phases.


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Figure 5-2. Most commonly recorded species (more than 50) in 101 compared to 091.

Figure 5-3 shows the most common sightings according to status. Almost half of species

sighted this phase are resident breeders (45 %), with the winter (non breeding) visitors

being the second most common category (38% while in the previous phase, 094, it was of

31 %). The 17 % left belongs to the status of breeding colony. Neither transient migrants

nor summer resident breeders were sighted during this phase.


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Figure 5-3. Bird sightings by status.

A similar proportion is observed for the more sighted species (more than 50) since six

individuals are resident breeders, three are winter visitors and two are breeding colony.

As expected, the percentage of winter visitors is higher than in the previous phase (094)since 101 is a fully winter phase (figure 5-3). Some species already sighted in 094 started

to be more common in 101, such as the Yellowthroat warbler (from one individual in 094 to

16 in 101), the Roseate spoonbill (from 19 individuals in 094 to 35 in 101) and the

Sandwich tern (from no individuals in 094 to 25 in 101).

5.5 Discussion

The Yucatan peninsula lies along a major migratory route for many species of birds.

Fluctuations in the presence and numbers of many species are therefore expected to be

observed between phases, reflecting seasonal migration or breeding patterns, whether

localised or widespread. 101 is a winter phase, which explains the higher number of winter

visitors and the lack of summer resident breeders.


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The comparison between phases at the same time of year is expected to show the

presence of the same types of migratory species. This was verified since the more sighted

birds (more than 50 sightings) were similar in both phases. Proportions vary between

phases, which can represent either a fluctuation in population or in recording and recorder

differences between years.

Most of the species observed during this phase are resident breeders. It is probable that

resident individuals were observed regularly and that their home ranges would cover more

than one transect area, as all 5 of the transects are relatively close together. This would

account for the apparently high frequency of some species, but this could only be

assessed by marking individuals, which is unlikely to happen.

5.6 Limitations and error

There have been several changes in methodology since the project was initiated in 2006,

which makes it difficult to make a direct comparison of the data over the 3 years of

surveying. These changes include a standardisation of the monitoring to ensure equal

numbers of transects are surveyed. The project also initially included incidental sightings

and made use of mist-netting by visiting bird experts. Mist-netting has not been available

recently and so cannot be included in the data, although if available in future it will be

invaluable to further increase the species list and improve the identification skills of

observers. Another change this year is to limit identification by sound to the more

distinctive species, as call recognition proved to be extremely difficult for inexperienced

observers. Time and personnel limitations mean that there have also been variations in

numbers of observers and in the length of time spent on a transect on different days,

which may have influenced the results. The new methodology must be applied over a few

years before we will have sufficient data to extract any long-term trends.

Besides the above-mentioned changes in methodology over time, another source of bias

is to do with the difficulty of observing and identifying bird species. Despite the efforts done

to correctly identify birds, in some cases, individuals can only be identified to family level.

In other cases they are not identified at all or perhaps mis-identified because of the

difficulty observing them, either because of their cryptic colouration, enclosed habitat,


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similarity with other species (e.g. Tyrannus kingbirds) or being simply too active or shy to

observe closely.

The experience level and number of observers could also affect identification: as

observers become more accustomed to observing birds and learn to recognise individual

species, they are more likely to notice those individuals and improve on their observational

skills with time, which might be reflected in the data collected throughout the time.

For the reasons above mentioned, this study is probably not sufficiently accurate to obtain

scientificly robust data about populations in the area, but it can achieve the aims of this

bird project by giving an idea of diversity, improving identification skills and increasing

awareness of the ecosystem among the VOLUNTEERs, and of increasing the species list

for the area.

5.7 Future work

We will aim to further reduce variation between transects as much as possible; so that a

long term data-base can be obtained that will hopefully show any trends. Despite the

limitations of the methodology, it would be interesting to apply statistical analysis once a

sufficiently large data set has been gathered to determine if there are significant changes

over time.

We will continue to expand on the species list for the area, working with visiting bird

experts to ensure that we build on our birding programme and draw on their expertise to

help staff and VOLUNTEERs at Pez Maya to identify the common bird species in the

reserve.


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6. Community Work

This phase we had a lot of community work. The army came twice to receive Englishlessons. We went several times to encourage them to come but they didnt. The fact that

they change their staff every month makes difficult to continue with the lessons. However

we will try again next phase.

We visited Punta Allen 9 times. With the 6 to 8 years old group we worked with different

things like body parts, numbers, colours, professions, transportation, shapes, and played

different games to reinforce the knowledge.

With the older group we worked with the tenses: present, past, present continuos andfuture.

We invited the Kids club to come to Pez Maya to have different activities. This times the

parents were involved and they received and EFR child care course. All the mothers

watched the EFR video and also had a practical session where they had to practice with

the baby dummy. They also participated on other games.

The children received a talk about the Rainbow parrotfish life cycle to explain theimportance of the mangroves, lagoon and the reef. After that, they had a game where they

had to collect some food to survive, first on the mangrove, then on the lagoon and finally

on the reef. They also played to put the right part of the body on the fish. We had another

talk about rubbish where the participated a lot. After that, we showed them some

handcrafts that they can make with rubbish and also we had three games. One the first

one they had to throw the rubbish in the right place; on the second one, they had to

separate the rubbish i

gvi pez maya quarterly report january- march 2010

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