managing lower trophic level species in the mid-atlantic region
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Managing Lower Trophic Level Species in the Mid-Atlantic Region. Forage Fish Workshop Mid-Atlantic Fishery Management Council Raleigh, North Carolina 11 April 2013 E. D. Houde. Northwest Atlantic Coastal and Shelf Ecosystems. Productive Coastal Zone Major Productive Estuaries - PowerPoint PPT PresentationTRANSCRIPT
Managing Lower Trophic Level Species in the Mid-Atlantic Region
Forage Fish WorkshopMid-Atlantic Fishery Management Council
Raleigh, North Carolina11 April 2013
E. D. Houde
Northwest Atlantic Coastal and Shelf Ecosystems
Productive Coastal Zone
Major Productive Estuaries
Connected to Southern NewEngland and Georges Bank
Connected to South Atlanticshelf ecosystems
Bounded by the Gulf Stream
Strongly seasonal
Primary Production
Chlorophyll a
Productivity of NW Atlantic ShelfEcosystems
NEFSC Ref Doc 12-07
Productivity on a par with SouthernNew England and Georges Bank
Candidate MA Forage SpeciesSpecies Fished Retained Discarded
Bycatch Bycatch___________________________________________________________________Butterfish yes yes yesAtl. mackerel yes no yesLongfin squid yes yes yesIllex squid yes yes yesAtl. herring yes ? yesAtl. Menhaden yes no yesRiver herrings no no ? yesSand lance no no noRound herring no no yesSardines no no ?Anchovies no no ?
Who are the Major Predators?
MAFMC SSC ESC “Definition
Is this a forage stock?
Is the stock retained in a fishery?
Is this a bycatch only fishery?
Is there an accepted stock assessment/ w/OFLs?
Does SA consider predation at all?
Does SA include predation directly (M2)?
Regular info input to OFL/ ACL/ABC process
Y
N
Y
Y
>
Y
NY
N
N
N
N
<, =
Y
Stop, Apply Regular ABC Control Rules
Treat as NS 1 Ecosystem Component species
Are Landings (catch) stable?
Mild increase to OFL buffer
Apply Regular ABC Control Rules
Address in Primary fishery
Decrease to OFL buffer
Are stock catch (landings, or B proxies) <, =, or > PP threshold?
Increase buffer to OFL proxy
Y N
NEW
Are there adequate catch (landings) data? Y
NAre there adequate biomass data?
Y (Use B proxies)
NGet data, be
precautionary
0
5
10
15
20
25
30
35
40
45
0 0.5 1 1.5 2 2.5 3
B/Bmsy
Prob
abili
ty o
f Ove
rfis
hing
typicalatypical
forage
Managed Forage Species
Modified Council Risk Policy
Can the MAFMC Develop a Forage Policy?
North Pacific Council Ecological Considerations for Forage
• Groundfish FMPs have a forage category as part of the ecosystem component (EC) of the fishery (8 families and 1 order); directed federal fisheries prohibited with 2% (fish on board) bycatch cap for this EC forage group
• M2 (predation mortality) term incorporated in stock assessments (where possible); increasing number of multi-species assessment models being developed
• PDTs and SSC evaluate trends in M due to predation when setting ABC for target species (may reduce ABC below max allowed if warranted)
• Increased biomass thresholds for commercially-important prey species to insure adequate forage for Stellar sea lions (reduced fishing as biomass thresholds are approached);
• Time/area restrictions to avoid local depletion• Ecosystem Considerations Report appended to groundfish and crab SAFE
documents • Established system OY cap for BSAI (85% of sum of MSYs for managed
species) and GOA groundfish fisheries (95% of sum of MSYs for managed species)
• Most recently developed Arctic FEP which includes system level cap=zero
PFMC Coastal Pelagics Species (CPS) FMP
• Includes Pacific sardine, chub mackerel, northern anchovy, jack mackerel, market squid, and krill (euphausids)
• Council banned harvest of krill in west coast EEZ (to prevent directed fishery development) in 2006
• Sardine and chub mackerel are actively managed, others are “monitored” species
PFMC: Amendment 13 (Sept 2011) to CPS FMP
• Modified existing harvest control rules to include ABC buffer relative to OFL through a combination of scientific advice from SSC and a policy determination of the Council (based on Council risk tolerance)
• Amendment 13 maintained default harvest control rules for monitored stocks (ABC equals 25% of OFL/MSY)
CPS Harvest Control Rules• Contain “cutoff” biomass reference points • Cut-off is defined as biomass level below which
directed fishing is prohibited
• Pacific sardine cutoff is 150,000 mt (or three times the overfished threshold); the control rule also contains environmental parameters to explicitly adapt harvest levels in response to environmental variability
Coastal Pelagic Species: PFMC Managed Species Control Rule
• OFL = Biomass x Fmsy x Distribution• ABC = Biomass x Buffer x Fmsy x Distribution• ACL ≤ ABC
General Harvest Control Rule
• HG = (Biomass – Cutoff) x Fraction x Distribution
• ACT = HG or ACL, whichever is less
• MAXCAT also is defined
The Harvest Control Rule Assures that Exploitation Rate Declines Continuouslyas Biomass Declines
PFMC FEP Initiative 1• Council proceeding with development of FEP
Initiative 1 – protection for un-fished forage species
• Objective is to prohibit development of new directed fisheries on forage species until Council has adequate opportunity to assess the science relating to any proposed fishery and any potential impacts to existing fisheries and communities
• Developed inventory of un-fished forage species and currently authorized gears and fisheries in US west coast EEZ
SSC National Workshop IV: EBFM and Forage Fish Issues
• Need better ways to estimate forage biomasses
• Need better ways to estimate predator demand
• Determining M2 is important• Ecosystem forage buffers vs single-
species buffers?
For consideration• Indicators and reference points• Are there any rules of thumb, e.g., F < M, Biomass
threshold, hockey-stick (Restrepo, Lenfest) rules, appropriate F and B levels.
• Can predator demand be indexed from stock assessments of predators?
• What indices of ecosystem state are available that are indicative of predator demand and prey availability?
• Can energetics modeling be useful to estimate demand?• What about ecosystem modeling? Strategic or tactical?• What decisions and regulations could be implemented
by managers in the short term?
Leave one third for the birds
Cury et al. 2011
Atlantic Menhaden
Y = -1.03 X – 2.73
phytoplankton
mesozooplankton
Fish larva
Zooplanktivoroussmall fish
Piscivorouslarge fish
Log 2
A (a
bund
ance
)
200 m 2 mm 20 mm 20 m 20 cm2 m Organism Size
Chesapeake Bay Integrated Biomass Size Spectrum(combined 1997 and 1999 data)
Bluefish
Weakfish
Striped Bass
Predators/PiscivoresCommercial Fishery
What is a “Fair” Allocation Plan?
Can Humans Cause “Localized Depletion?” Recreational Striped Bass Fishing
Osprey
Menhaden: Allocation and EBFM