1

CLIMATE CHANGE

AND

IMPLEMENTATION OF CCAMLR’S OBJECTIVES

THE ANTARCTIC AND SOUTHERN OCEAN COALITION

(ASOC)

Paper for XXVI Meeting of CCAMLR, October-November 2007

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Climate Change

and

Implementation of CCAMLR’s Objectives

1. INTRODUCTION

Article IX (1) of the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) establishes that the function of the Commission is to “give effect to the objective and principles set out in Article II”. Central to Article II are the “principles of conservation” itemized in paragraph 3:

Any harvesting and associated activities in the area to which this Convention applies shall be conducted in accordance with the provisions of this Convention and with the following principles of conservation:

(a) prevention of decrease in the size of any harvested population to levels below those which ensure its stable recruitment. For this purpose its size should not be allowed to fall below a level close to that which ensures the greatest net annual increment;

(b) maintenance of the ecological relationships between harvested, dependent and related populations of Antarctic marine living resources and the restoration of depleted populations to the levels defined in sub-paragraph (a) above; and

(c) prevention of changes or minimisation of the risk of changes in the marine ecosystem which are not potentially reversible over two or three decades, taking into account the state of available knowledge of the direct and indirect impact of harvesting, the effect of the introduction of alien species, the effects of associated activities on the marine ecosystem and of the effects of environmental changes, with the aim of making possible the sustained conservation of Antarctic marine living resources.

Plainly, a number and variety of factors are potentially significant in relation to these principles. But there can be little doubt, based upon the contemporary scientific advice (much of it based on research conducted in the Convention and Antarctic Treaty Areas), that climate change constitutes a major pressure (indeed, in most estimations the greatest pressure) upon the Antarctic marine environment. Unavoidably, therefore, the Commission must address itself to the effects of climate change. Unless it does so, the supposed ecosystem focus of the Convention is undermined and the Commission would be in default of its obligations.

CCAMLR can play an important role in monitoring the effects of climate change on marine ecosystems and species, regularly reporting on the likely effects and consequences that climate change may have on the Antarctic marine environment in the Convention Area.

ASOC is calling for clear steps on the part of the Commission to give effect to its duties under the Convention in relation to the global challenge posed by climate change, as well as longer-term steps taken in concert with Antarctic Treaty Consultative Parties.1

1 ASOC introduced papers on climate change at recent ATCMs. See: XXX ATCM IP 82 rev 1 (2007) and XXIX ATCM IP 62 (2006), which recommend medium-term steps by ATCPs to meet their climate change stewardship

obligations for the Antarctic. ASOC recommends that CCAMLR Parties work closely with the ATCM and CEP on

steps to address climate change that will help fulfill the Parties’ global obligations under the Framework Convention on Climate Change, including (1) establishing an obligation to record the greenhouse gas emissions

from vessels of all types associated with CCAMLR fishing, from vessels and aircraft used by CCAMLR Parties and Antarctic Treaty Consultative Parties to carry out research and supply and operate stations, and other

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This paper urges CCAMLR to apply the precautionary approach given (i) the converging knowledge about the impacts and implications of climate change on the Southern Ocean, and (ii) the uncertainty about the effects of climate effects on different elements of the ecosystem and how those effects may be exacerbated by fishing. ASOC recommends that CCAMLR’s Commission take full account of the rapidly evolving situation and the latest scientific evidence as it designs and implements management decisions on marine living resources in Antarctica. The need to incorporate the effects of climate change into fisheries management has become clear in the case of Antarctic krill but it should also be taken into account in all CCAMLR management decisions.

The paper includes background information in relation to climate change and ozone depletion impacts on Antarctic marine ecosystems, species and habitats. Appendix 1 discusses climate change effects on Antarctic ecosystems, Appendix 2 covers impacts of ozone depletion on Antarctic ecosystems, Appendix 3 reprises glacial retreat and ice-shelf loss in the Antarctic, Appendix 4 notes a new legal initiative regarding penguins and climate change, and Appendix 5 provides abstracts from recent papers on the effects of climate change and ozone depletion on Antarctic ecosystems.

2. CLIMATE CHANGE AND ITS RELEVANCE FOR CCAMLR

CCAMLR should take fully into account the latest scientific evidence on implications related to the significant changes experienced by Southern Ocean marine species and their habitats, and particularly to factors that may affect the ability of target species to maintain their reproductive potential. This should be considered as the Commission makes management decisions, including but not limited to, the establishment of annual catch limits for target species.

The relevance of climate change for CCAMLR work merits the incorporation of an agenda sub-item that allows Members to discuss and review work underway in relation to the impact of climate change in Antarctic marine ecosystems. This should include monitoring efforts to detect and understand climate change impact, and the degree to which management decisions take into account the effects of climate change on target, dependent and related species.

A. Long-term Ecosystem Monitoring

At ATCM XXIX Resolution 3 (2007) was adopted, on Long-term Scientific Monitoring and Sustained Environmental Observation in Antarctica. The Resolution supports long-term monitoring and sustained observations of the Antarctic environment and associated data management as a primary legacy of the IPY, in order to increase the capacity to detect, understand and forecast the impacts of climate change. Specifically, the Resolution urges national Antarctic programmes to maintain and extend long-term research and monitoring in order to observe environmental changes. It also recommends that Antarctic Treaty Consultative Parties (ATCPs) contribute to a “coordinated Antarctic observing system network”, initiated during the IPY, in cooperation with relevant international bodies including CCAMLR.

CCAMLR’s Ecosystem Monitoring Program (CEMP) was established in 1985 in order to monitor the effects of fishing on both target and dependent species. One of its tasks is to distinguish the effects of fishing from environmental effects such as climate change. When discussing the importance of environmental monitoring and reporting, the CEP has acknowledged that CEMP’s experience in ecosystem monitoring over the last 20 years could be a valuable asset for the CEP when developing a monitoring program for the Antarctic.2

vessels and aircraft coming to and from the Antarctic – for example from tourism, and (2) take steps both individually and collectively to reduce the greenhouse gas emissions from those sources and develop means to

offset their emissions, with the goal of Antarctic activities being carbon neutral.

2 CEP IX, Edinburgh, paragraphs 160-162

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In the context of the IPY and Resolution 3 (2007) referenced above, CCAMLR could play a vital role in the establishment of the proposed “coordinated Antarctic observing system network”. In order to achieve that goal, CCAMLR Members should intensify their monitoring efforts and increase their cooperation with the relevant international and Antarctic Treaty organisms.

B. Incorporating Climate Change into Management Decisions

CCAMLR XXV acknowledged “the need to address climate effects and to monitor such effects in relation to future potential changes in, and influences on, the species and area for which CCAMLR is responsible”. Members were invited to reflect on such advances and needs with a view to tabling ideas for further consideration at CCAMLR-XXVI.3

Specifically, the Scientific Committee has been considering the need to incorporate the effects of climate change into its management advice for the krill fishery. At the last CCAMLR meeting, the Scientific Committee requested CCAMLR Members to consider “what the potential effects of climate change on Antarctic marine ecosystems might be, and how this knowledge could be used to advise the Commission on management of the krill fishery”.4

Climate change has the potential to affect all species in the Antarctic marine ecosystem. Therefore, it is important that CCAMLR incorporates this element into its management decisions in a similar way as it is starting to do with the krill fishery.

C. Overview of Climate Change Implications for the Antarctic

The Antarctic Peninsula has experienced a major warming over the last 50 years. Winter temperatures have increased at 15 times the rate of global warming, making the Antarctic Peninsula, together with the Arctic, the regions that are warming fastest on Earth5. Over the past 61 years, 87% out of the 244 marine glacier fronts on the Antarctic Peninsula and associated islands have retreated, and the clear boundary between mean advance and retreat has migrated progressively southward.6 Sea ice has decreased in both concentration and duration around the Antarctic Peninsula and in the southern Bellingshausen Sea, although as part of the same altered climate system (the Southern Annular Mode) increases have been observed in the western Ross Sea.7 The troposphere over the Antarctic continent (the lowest layer of the atmosphere, extends to approximately 8 km above ground) also has warmed significantly over the past 30 years, accompanied by a concurrent cooling in the stratosphere (the layer of the atmosphere above that of the troposphere). This phenomenon is consistent with what would be expected as a result of increasing greenhouse gases.8 In addition, the Southern Ocean has been in a

3 CCAMLR XXV Commission Report, paragraphs 17.4 and 17.5.

4 SC Report, 2006.

5 According to Turner, J., Colwell, S.R., Marshall, G.J., Lachlan-Cope, T.A., Carleton, A.M., Johnes, P.D., Lagun,

V., Reid, P.A. and Iagovkina, S. (2005) Antarctic climate change during the last 50 years. International Journal of

Climatology, 25, 279-294, the Antarctic Peninsula has been warming at 1.09°C per decade over the winter.

According to IPCC, Climate Change 2007 – The Physical Basis, the global surface temperature has increased by

0.74°C per century.

6 Cook, A.J., Fox, A. J., Vaughan, D. G., Ferrigno, J. G. (2005), Retreating glacier fronts on the Antarctic

Peninsula over the past half-century. Science, 308, 541-544.

7 Parkinson, C.L. (2004) Southern Ocean sea ice and its wider linkages: insights revealed from models and

observations. Antarctic Science, 16(4), 387-400; Stammerjohn, S.E., Martinson, D.G., Smith R.C., Yuan, X., and

Rind, D. (2007) Trends in Antarctic annual sea ice retreat and advance and their relation to ENSO and Southern Annular Mode variability. J Geophysical Research, in press.

8 Turner, J., Lachlan-Cope, T.A., Colwell, S., Marshall, G.J., Connolley, M. (2006) Significant Warming of the Antarctic Winter Troposphere. Science, 311 (5769), 1914-1917.

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state of disequilibrium with its atmosphere and cryosphere during recent decades. It has become less salty and has warmed to a greater depth than previously, down to 3,000 m.9

State-of-the-art climate models project further decline in Antarctic sea ice through the 21st century as a result of global warming. Krill and other organisms depend upon a reliable seasonal pack ice cycle of advance and retreat to reproduce. Long and extended pack ice coverage during winter months provides refuge for krill against predation and a favorable habitat for the ice-algae upon which krill forage. Ice-algae are a critical food source for juvenile krill during the winter and early spring. A study conducted in 2004 found that, coincident with a decline in sea ice, krill populations in certain areas of the South West Atlantic have declined significantly since the 1970s10 (up to 80% in one region). It was also found that sufficient winter ice in the Antarctic Peninsula and Southern Scotia Arc, which are major krill spawning and nursery areas, affects krill density across the whole ocean basin, including areas north of the Seasonal Ice Zone. The loss of sea ice is likely behind the decline as well as declines in pack-ice dwelling fish species, such as the silverfish Pleuragramma antarcticum, another critical species in neritic areas of the Southern Ocean. 11

One species to feel the effects directly is the Adélie penguin, Pygoscelis adeliae. Quoting a recent article featuring the work of David Ainley and William Fraser:

“Along the tip of the Antarctic Peninsula, which reaches farther north than anywhere else on the continent, average annual temperatures have risen 4.5 degrees in just the last 30 years. By comparison, the Earth’s annual temperature has increased by 1.4 degrees in the last century. In this vulnerable area, entire colonies of Adélie penguins have disappeared because, researchers believe, the ice no longer extends far enough into the sea to allow the birds to reach their winter feeding grounds. Biologist William Fraser monitors a 50-square-mile area where 56,000 Adélies have perished. “For our region I work in, the Adélies will be locally extinct within a decade,” Fraser said. “One of the colonies we worked on for 30 years went extinct last year, from 1,000 breeding pairs to zero.”12 “Climate change is very serious stuff, and that’s the message Adélie penguins have been telling us,” Ainley said. “Humans have to learn lessons from what these penguins are going through.”

9 Jacobs, S. (2006) Observations of change in the Southern Ocean. Philosophical Transactions of the Royal

Society A, 364, 1657-1681.

10 Atkinson, A., Siegel, V., Pakhomov, E., Rothery, P. (2004) Long term decline in krill stock and increase in salps

within the Southern Ocean. Nature, 432, 100-103.

11 La Mesa, M., Eastman, J. T., Vacchi, M., The role of notothenioid fish in the food web of the Ross Sea shelf

waters: a review, Polar Biology (2004) 27: 321–338, DOI 10.1007/s00300-004-0599-z. See also Emslie, S.E.,

McDaniel, J.D. (2002), Adélie penguin diet and climate change during the middle to late Holocene in northern Marguerite Bay, Antarctic Peninsula, Polar Biology, 25, 222-229.

12 Penguins' struggle is a warning to world, William Mullen, Chicago Tribune (MCT), 11 July 2007, p. 2. http://www.popmatters.com/pm/news/article/43748/penguins-struggle-is-a-warning-to-world/

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3. ASOC RECOMMENDATIONS

ASOC urges CCAMLR Members to take the following steps at XXVI CCAMLR:

o Adopt a Resolution acknowledging that climate change is a major factor currently affecting the Southern Ocean, committing CCAMLR Members to take steps in the Convention Area towards avoiding further irreversible ecosystem change, including encouraging CCAMLR and CCAMLR Members’ participation in a “coordinated Antarctic observing system network”.13

o Establish a Commission standing agenda sub-item - "Consequences of climate change" – under Agenda item 17 - Implementation of the Objectives of the Convention.

o Establish mechanisms, including increased monitoring efforts under CEMP, whereby CCAMLR can identify and annually report on the likely effects and consequences that climate change may have on the Antarctic marine environment in the Convention Area.

13 This was proposed by ATCM Resolution 3 (2007). It would be important for CCAMLR to highlight the role of CEMP in such a network.

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Appendix 1

Climate Change and Southern Ocean Marine Ecosystems

As climate change impacts Antarctica, the sensitive marine ecosystem’s components are exposed to changing conditions that make predicting the future difficult, but the downward trends are clear.14

“Of the changes observed in the marine ecosystem of the Western Antarctic Peninsula (WAP) region to date, alterations in winter sea ice dynamics are the most likely to have had a direct impact on the marine fauna, principally through shifts in the extent and timing of habitat for ice-associated biota. Warming of seawater at depths below ca 100 m has yet to reach the levels that are biologically significant. Continued warming, or a change in the frequency of the flooding of Circumpolar Deep Water (CDW) onto the WAP continental shelf may, however, induce sublethal effects that influence ecological interactions and hence food-web operation. In addition, a southwards shift of marine isotherms may induce a parallel migration of some taxa similar to that observed on land.”15

What this means to the Southern Ocean directly is that coastal waters are becoming more dilute and thus less saline.8 How the food web will be affected is a subject yet to be broached. As an example, ocean density, in which salinity is the key variable, is important to the ontogenic vertical migration of krill eggs and early life history stages. The concurrent warming and dilution of CDW - the water that is upwelled at the continental margin and which is important in the seasonal cycles of Antarctic krill - is also a subject requiring important and directed research if we are to understand how climate change will affect the role of krill in the food web.16

The decline of krill in the Scotia Sea region is linked to loss of sea ice. In this geographical region, such a massive reduction in krill stocks, in conjunction with declining fish abundance, linked both to climate and fishery depletion, has serious adverse implications for middle- and upper-trophic levels.17 Far less is known about relations with sea ice change of the coastal, sea-ice dwelling Antarctic silverfish. It, too, is a key predator and prey in coastal, ice-covered waters, and it is disappearing coincident with sea ice loss in waters off the western shores of the Antarctic Peninsula.

The implications of these changes are profound. For one, a declining availability of Antarctic krill and coastal fish, as a result of climate change, likely would limit the capacity of baleen whales and depleted fish stocks to even approach historical levels, or those levels deemed to qualify as population recovery.

Finally, ocean acidification caused by increased carbon dioxide levels is raising concerns over the potential for large-scale changes to the Antarctic ecosystem.18 The IPCC’s latest assessment projects a decrease in “average global surface ocean pH of between 0.14 and 0.35 units over the 21st century,

14 Extreme sensitivity of biological function to temperature in Antarctic marine species, Peck, L, Webb, K.E.,

Bailey, D.M.

15 Climate change and the marine ecosystem of the western Antarctic Peninsula: Rogers, A.D., Murphy, E.,

Clarke, A.,Johnston, N. (2007)

http://www.journals.royalsoc.ac.uk/content/u695582087w7/, Volume 362, Number 1477 / January 29, 2007

16 Ducklow et. al. 2007

17 Atkinson, A., Siegel, V., Pakhomov, E., Rothery, P. (2004) Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature 432: 100-103); Myers, R.A. Worm, B. (2003) Rapid worldwide depletion of

predatory fish communities. Nature 423, 280-283; Pauly, D., Christiansen, V., Dalsgaard, J., Froeser, R., Torres Jr., F. (1998) Fishing down marine food webs. Science 279, 860-863; Pauly, D., Watson, R., Alder, J. (2005)

Global trends in world fisheries: impacts on marine ecosystems and food security. Philosophical Transactions of

the Royal Society B 360, 5–12; Kock, K-H. (1992) Antarctic fish and fisheries. Cambridge University Press, Cambridge and New York.

18 Wright, S., Davidson, A. (2006) Ocean acidification: a newly recognised threat. Australian Antarctic Magazine. Autumn 2006, pp. 26-27.

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adding to the present decrease of 0.1 units since pre-industrial times.”19 A decrease in pH of 0.5 in the surface oceans corresponds to a three-fold increase in the concentration of hydrogen ions. Such a decrease in pH will have negative consequences, primarily for oceanic calcifying organanisms. Calcifying organisms in the Southern Ocean are likely to be among the first to be affected from ocean acidification.20 Most at risk are the aragonite-producing pelagic molluscs (pteropods), which are thought to be the dominant calcifiers in the Southern Ocean.

19 IPCC (2007) Climate Change 2007: The Physical Science Basis: Summary for Policymakers - Contribution of

Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Feb 2007,

18p.

20 Raven, J. et al. (2005). Ocean acidification due to increasing atmospheric carbon dioxide. The Royal Society.

London 57 pp. http://www.royalsoc.ac.uk/document. asp?id=3249.

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Appendix 2

Ecosystem Impacts of Antarctic Ozone Depletion

zone depletion, caused by anthropogenic pollution of the atmosphere and discovered by scientists more the 20 years ago, results in an increase in the amount of biologically harmful UV-B radiation that reaches the Earth's surface and that penetrates into the surface waters of the oceans. Dr. Fraser and Dr. Karentz have observed, for example, that increased levels of UV-B radiation in the Antarctic provoke a range of changes in marine organisms, such as impairment of metabolic processes, decreases in growth, reduction in reproductive potential, morphological abnormalities, genetic damage, and death.21

The evidence suggests that UV-induced damage to specific organisms can initiate various degrees of disruption in marine ecosystems, upsetting the balance between organisms and their environment. Research conducted in the Antarctic indicates that the amount of biological damage to marine organisms is directly correlated to the level of ozone depletion. It has also been observed that Antarctic organisms have differential sensitivities to UV exposure such that a dose of UV that is lethal to one species may only cause impairment in another. The combination of protection and repair capabilities varies among species and will influence survival, growth, and reproductive success under UV-B stress. Because each species responds differently, shifts in species composition (biodiversity) are expected under an increased UV-B regime. Even subtle alterations in the quantity or quality of food sources (phytoplankton and krill) can ultimately affect the larger Antarctic consumers such as penguins, seals, and whales. Because the Antarctic marine ecosystem is directly linked to the rest of the world's oceans, changes in the Antarctic region can initiate changes in the rest of the biosphere. We need, therefore, to understand better what these changes might be and what impacts they could have on humans and other ecosystems.

This is particularly relevant for CCAMLR given the latest evidence about the size of the annual ozone hole over the Antarctic and the reality that it is appearing earlier than ever this year.22 "Although ozone-depleting substances are now declining slowly, there is no sign that the Antarctic ozone hole is getting smaller," said the WMO report. The WMO and the U.N. Environment Programme have said the ozone layer would likely return to pre-1980 levels by 2049 over much of Europe, North America, Asia, Australasia, Latin America and Africa. But in Antarctica, the agencies said, ozone layer recovery would likely be delayed until 2065.23

21 Fraser, W., Karentz, D., Antarctic Update, USGCRP Seminar, 1997.

22 Antarctic ozone hole early in 2007, August 28, 2007.

http://www.reuters.com/article/environmentNews/idUSL2829160820070828

23 Ibid.

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Appendix 3

Melting Glaciers and Disintegrating Ice Shelves

British Antarctic Survey (BAS) studies in 2005 of the melting of Antarctic Peninsula glaciers indicate that they are losing mass much faster than previously predicted. Some researchers have concluded that the melting of these glaciers is already likely contributing a non-negligible part to sea level rise.24 In the Amundsen Sea sector of West Antarctica, accelerating glacier melt is now discharging enough excess ice to raise sea level more than 0.2 mm per year. This is the sector widely believed to be the most vulnerable portion of the West Antarctic Ice Sheet (WAIS), with the potential for a further rapid acceleration of ice discharge.25 The recent rapid collapse of a significant part of the Larsen Ice Shelf off the northern Antarctic Peninsula has refocused discussion on implications of ice shelf decay for the stability of Antarctica's grounded ice. Records from six marine sediment cores in the vicinity of the Larsen Ice Shelf demonstrate that the recent collapse of Larsen B is unprecedented during the Holocene - since the end of the last ice age more than 12,000 years ago. This research implies that the Larsen B Ice Shelf has been thinning throughout the Holocene, but the recent elevated period of warming has led to its collapse.26

Satellite radar measurements show that ice shelves in Pine Island Bay have thinned by up to 5.5 m/year over the past decade. The thinning of the ice shelves, apparently from ocean currents on average 0.5°C warmer than freezing, is mirrored by the thinning of their tributaries - Pine Island, Thwaites and Smith glaciers. The imbalance of the glaciers in response to the thinning of the ice shelves shows that Antarctica is more sensitive to changing climates than was previously considered.27 A growing body of observational data suggests that Pine Island Glacier is changing on decadal or shorter time scales. These changes may have far-reaching consequences for the future of the WAIS and global sea levels because of the glacier's role as one of the ice sheet's primary drainage portals. The speed at which these changes are propagated upstream implies a tight coupling between the ice-sheet interior and the surrounding ocean.28 Indeed, the rate of flow of these glaciers is sensitive even to the weak ebb and flow of Antarctic tides. Antarctic Peninsula glaciers that fed the former Larsen B Ice Shelf have also sped up by factors of two to eight following the collapse of the ice shelf in 2002. In contrast, glaciers further south did not accelerate as they are still buttressed by a grounded ice shelf. The mass loss associated with the flow acceleration exceeds 27 cubic kilometers (0.07 mm sea level) per year and ice is thinning at rates of tens of meters per year. This abrupt evolution of the glaciers is attributed to the removal of the buttressing ice shelf. The magnitude of the glacier changes illustrates the importance of ice shelves on ice sheet mass balance and contribution to sea level change.29

24 Rignot, E., Casassa, G., Gogineni, S, Kanagaratnam, P., Krabill, W., Pritchard, H., Rivera, A, Thomas, R.,

Turner, J., Vaughan, D. (2005) Recent ice loss from the Fleming and other glaciers, Wordie Bay, West Antarctic Peninsula. Geophysical Research Letters, 32(7), L07502, doi:10.1029/2004GL021947.

25 Thomas et al., 2004, op.cit.

26 Domack, E., Duran, D. Leventer, A. Ishman, S. Doane, S. McCallum, S. Amblas, D. Ring, J. Gilbert, R.,

Prentice, M. (2005) Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch.

Nature, 436(7051), 681-685.

27 Shepherd, A., Wingham, D., Rignot, E. (2004) Warm ocean is eroding West Antarctic Ice Sheet. Geophysical

Research Letters, 31(23), L23402, doi:10.1029/2004GL021106..

28 Payne, A.J., Vieli, A., Shepherd, A.P., Wingham, D.J., Rignot E. (2004) Recent dramatic thinning of largest

West Antarctic ice stream triggered by oceans. Geophysical Research Letters, 31(23), L23401,

doi:10.1029/2004GL021284.

29 Rignot, E., Casassa, G., Gogineni, P., Krabill, W., Rivera, A., and Thomas, R., 2004. Accelerated ice discharge

from the Antarctic Peninsula following the collapse of Larsen B ice shelf. Geophysical Research Letters, 31(18), L18401, doi:10.1029/2004GL020697.

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Appendix 4

A Recent Legal Development

There are some interesting legal developments regarding the Antarctic and climate change. On July 11, 2007 the U.S. Fish and Wildlife Service (FWS), responding to a petition from the Center for Biological Diversity,30 took the first step toward evaluating the question of whether the emperor penguin (Aptenodytes forsteri) and macaroni penguin (Eudyptes chrysolophus), two Antarctic species among 10 penguin species total, fall under the protection of the U.S. Endangered Species Act.31 Factors to be examined in the birds' status will be the effects of climate change and fisheries on their food supply. The FWS acknowledged that it has enough evidence to begin a full-scale review of these species.32

30 The petition was filed November 28, 2006.

31 37695 Federal Register/Vol. 72, No. 132/Wednesday, July 11, 2007/Proposed Rules, p. 37695.

32 International Herald Tribune, “U.S. agency moves to protect penguins”, Felicity Barringer, July 7, 2007. A news

release from the CBD said the emperor penguin colony in Antarctica that was featured in the 2005 film March of the Penguins "has declined by more than 50 percent because of global warming." The 10 species named by

FWS include the macaroni, a species in CCAMLR’s ecosystem monitoring program.

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Appendix 5

Abstracts on Climate Change and Marine Ecosystems

A. GENERAL IMPACTS ON ECOSYSTEMS

Climate change and the marine ecosystem of the western Antarctic Peninsula, Rogers, A.D., Murphy, E., Clarke, A., Johnston, N., Proceedings of the Royal Society, Vol. 362, No. 1477, January 29, 2007 http://www.journals.royalsoc.ac.uk/content/u695582087w7/

Abstract: The Antarctic Peninsula is experiencing one of the fastest rates of regional climate change on Earth, resulting in the collapse of ice shelves, the retreat of glaciers and the exposure of new terrestrial habitat. In the nearby oceanic system, winter sea ice in the Bellingshausen and Amundsen seas has decreased in extent by 10% per decade, and shortened in seasonal duration. Surface waters have warmed by more than 1K since the 1950s, and the Circumpolar Deep Water (CDW) of the Antarctic Circumpolar Current has also warmed. Of the changes observed in the marine ecosystem of the western Antarctic Peninsula (WAP) region to date, alterations in winter sea ice dynamics are the most likely to have had a direct impact on the marine fauna, principally through shifts in the extent and timing of habitat for ice-associated biota. Warming of seawater at depths below ca 100m has yet to reach the levels that are biologically significant. Continued warming, or a change in the frequency of the flooding of CDW onto the WAP continental shelf may, however, induce sublethal effects that influence ecological interactions and hence food-web operation. The best evidence for recent changes in the ecosystem may come from organisms which record aspects of their population dynamics in their skeleton (such as molluscs or brachiopods) or where ecological interactions are preserved (such as in encrusting biota of hard substrata). In addition, a southwards shift of marine isotherms may induce a parallel migration of some taxa similar to that observed on land. The complexity of the Southern Ocean food web and the nonlinear nature of many interactions mean that predictions based on short-term studies of a small number of species are likely to be misleading.

Spatial and temporal operation of the Scotia Sea ecosystem: a review of large-scale links in a krill centered food web, Murphy, E.J., Watkins, J.L., Trathan, P.N., Reid, K., Meredith, M.P, Thorpe, S.E., Johnston, N.M., Clarke, A., Tarling, G.A., Collins, M.A., Forcada, J., Shreeve, R.S., Atkinson, A., Korb, R., Whitehouse, M.J., Ward, P., Rodhouse, P.G., Enderlein, P., Hirst, A.G., Martin, A.R., Philosophical Transactions of the Royal Society B, Jan. 2007, Vol. 362, Issue 1477, 113-148.

Abstract: The Scotia Sea ecosystem is a major component of the circumpolar Southern Ocean system, where productivity and predator demand for prey are high. The eastward-flowing Antarctic Circumpolar Current (ACC) and waters from the Weddell–Scotia Confluence dominate the physics of the Scotia Sea, leading to a strong advective flow, intense eddy activity and mixing. There is also strong seasonality, manifest by the changing irradiance and sea ice cover, which leads to shorter summers in the south. Summer phytoplankton blooms, which at times can cover an area of more than 0.5 million km2, probably result from the mixing of micronutrients into surface waters through the flow of the ACC over the Scotia Arc. This production is consumed by a range of species including Antarctic krill, which are the major prey item of large seabird and marine mammal populations. The flow of the ACC is steered north by the Scotia Arc, pushing polar water to lower latitudes, carrying with it krill during spring and summer, which subsidize food webs around South Georgia and the northern Scotia Arc. There is also marked interannual variability in winter sea ice distribution and sea surface temperatures that are linked to southern hemisphere-scale climate processes such as the El Niño–Southern Oscillation. This variation affects regional primary and secondary production and influences biogeochemical cycles. It also affects krill population dynamics and dispersal, which in turn impacts higher trophic level predator foraging, breeding performance and population dynamics. The ecosystem has also been highly perturbed as a result of harvesting over the last two centuries and significant ecological changes have also occurred in response to rapid regional warming during the second half of the twentieth century. This combination of

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historical perturbation and rapid regional change highlights that the Scotia Sea ecosystem is likely to show significant change over the next two to three decades, which may result in major ecological shifts.

Alteration of the food web along the Antarctic Peninsula in response to a regional warming trend, Moline, M.A., Claustre, H., Frazer, T.K, Schofield, O. Vernet, M., Global Change Biology, Vol. 10, No. 12, 1973-1980, Dec. 2004.

Abstract: In the nearshore coastal waters along the Antarctic Peninsula, a recurrent shift in phytoplankton community structure, from diatoms to cryptophytes, has been documented. The shift was observed in consecutive years (1991-1996) during the austral summer and was correlated in time and space with glacial melt-water runoff and reduced surface water salinities. Elevated temperatures along the Peninsula will increase the extent of coastal melt-water zones and the seasonal prevalence of cryptophytes. This is significant because a change from diatoms to cryptophytes represents a marked shift in the size distribution of the phytoplankton community, which will, in turn, impact the zooplankton assemblage. Cryptophytes, because of their small size, are not grazed efficiently by Antarctic krill, a keystone species in the food web. An increase in the abundance and relative proportion of cryptophytes in coastal waters along the Peninsula will likely cause a shift in the spatial distribution of krill and may allow also for the rapid asexual proliferation of carbon poor gelatinous zooplankton, salps in particular. This scenario may account for the reported increase in the frequency of occurrence and abundance of large swarms of salps within the region. Salps are not a preferred food source for organisms that occupy higher trophic levels in the food web, specifically penguins and seals, and thus negative feedbacks to the ecology of these consumers can be anticipated as a consequence of shifts in phytoplankton community composition.

Paradigm lost, or is top-down forcing no longer significant in the Antarctic marine ecosystem?, Ainley, D., Ballard, G., Ackley, S., Blight, L.K., Eastman, J.T., Emslie, S.D., Lescroël, A., Olmastroni, S., Townsend, S.E., Tynan, C.T., Wilson, P., Woehler, E. Antarctic Science, Vol. 19, No. 3, 283-290, 2007

Abstract. Investigations of the ecological structure and processes of the Southern Ocean in recent years have almost exclusively taken a bottom-up, forcing-by-physical-processes approach relating various species’ population trends to climate change. Just 20 years ago, however, researchers focused on a broader set of hypotheses, in part formed around a paradigm positing interspecific interactions as central to structuring the ecosystem (forcing by biotic processes, top-down), and particularly on a “krill surplus” caused by the removal from the system of more than a million baleen whales. This latter idea has disappeared from favor with little debate. Moreover, it recently has been shown that concurrent with whaling was a massive depletion of finfish in the Southern Ocean, a finding also ignored in deference to climate-related explanations of ecosystem change. We present two examples from the literature, one involving gelatinous organisms and the other involving penguins, in which climate has been used to explain species’ population trends but which could better be explained by including species interactions in the modelling as well. We conclude by questioning the almost complete shift in paradigms that has occurred and discuss whether it is leading Southern Ocean marine ecological science in an instructive direction.

B. KRILL RESEARCH

Krill, Currents, and Sea Ice: Euphausia superba and Its Changing Environment, Nicol, S., BioScience, Vol. 56, No.2, p. 111, February 2006. www.biosciencemag.org

Abstract: Investigations of Antarctic krill (Euphausia superba) over the last 40 years have examined almost every aspect of the biology of these ecologically important animals. Various elements of krill biology have been brought together to provide concepts of how this species interacts with its environment, but there have been few recent attempts to generate a generalized conceptual model of its

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life history. In this article I present such a model, based on previous descriptions, observations, and recent data from the scientific literature. This model takes into account a range of findings on krill biology and on the relationships between Antarctic krill and its biotic and abiotic environment. Krill life history is thus viewed as an evolved product of interactions between the species and its environment. The model places particular emphasis on the different forces that act on the larval and adult stages, and on the interaction between krill behavior, systems of ocean currents, and sea ice.

Krill flux in Southern Ocean food-webs, Murphy, A.U., Watkins, E.J, Meredith, J.L., Ward, M.P., Trathan, P., American Geophysical Union, Paper presented at 2002 Ocean Sciences Meeting.

Abstract: That krill are transported in the current systems of the Southern Ocean is well established but there has been little quantification or assessment of the significance of such a horizontal flux. At South Georgia the local stock of krill is probably maintained by the input of krill from further south. Model studies have suggested that the Southern Antarctic Circumpolar Front (SACCF) may have a role in transporting krill into the region. Here we report an interdisciplinary study of the ocean to the north of South Georgia where the SACCF retroflects around the island. There was a strong jet associated with the westward flow SACCF and a weaker return flow to the east further offshore. There was an enhanced biomass of krill associated with the westward flow of the SACCF. Using vertically resolved estimates of water volume transport and krill biomass we have derived an estimate of krill flux in the region. Comparison of the integrated flux of krill with some of the estimated food-web fluxes in the region indicates that the flux component will have dominated the food-webs flows at this time. Using model studies and analyses of the development of the biological community we are considering the origin of the krill observed in the SACCF during the summer at South Georgia.

Advection, krill, and Antarctic marine ecosystems, Hofmann, P., Eugene E., Murphy, J., Antarctic Science, 16, No. 4, 487-499, 2004.

Abstract: Advective processes are recognized as being important in structuring and maintaining marine ecosystems. In the Southern Ocean advective effects are perhaps most clearly observed because the Antarctic Circumpolar Current (ACC) provides a connection between most parts of the system, including open ocean and continental shelf regions. The ACC also provides a mechanism for large-scale transport of plankton, such as Antarctic krill (Euphausia superba Dana), which is an important component of the Southern Ocean food web. This overview provides a summary of recent observational and modelling results that consider the importance of advection to the Southern Ocean ecosystem and, in particular, the role of advection in structuring the large-scale distribution of Antarctic krill. The results of these studies show that advection is a dominant process controlling Antarctic krill distribution and by inference an important process affecting overall structure and production of the Southern Ocean food web. The overview shows that quantifying the roles of advective and retentive physical processes, and population dynamic and behavioural biological processes in determining the regional and local distribution of krill and abundance will be an important research focus. Strategies for future Antarctic multidisciplinary research programmes that are focused on understanding advective processes at a circumpolar scale are suggested.

C. EFFECTS ON PREDATORS

Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability, Trathan, P.N., Forcada, J., Murphy, E.J., Philosophical Transactions of the Royal Society, 10.1098/rstb.2006.1953, May 24, 2007.

Abstract. The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly in the high-latitude polar regions. In these regions, even small temperature changes can potentially lead to major environmental perturbations. Climate change is likely to be regional and may be expressed in

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various ways, including alterations to climate and weather patterns across a variety of time-scales that include changes to the long interdecadal background signals such as the development of the El Niño–Southern Oscillation (ENSO). Oscillating climate signals such as ENSO potentially provide a unique opportunity to explore how biological communities respond to change. This approach is based on the premise that biological responses to shorter-term sub-decadal climate variability signals are potentially the best predictor of biological responses over longer time-scales. Around the Southern Ocean, marine predator populations show periodicity in breeding performance and productivity, with relationships with the environment driven by physical forcing from the ENSO region in the Pacific. Wherever examined, these relationships are congruent with mid-trophic-level processes that are also correlated with environmental variability. The short-term changes to ecosystem structure and function observed during ENSO events herald potential long-term changes that may ensue following regional climate change. For example, in the South Atlantic, failure of Antarctic krill recruitment will inevitably foreshadow recruitment failures in a range of higher trophic-level marine predators. Where predator species are not able to accommodate by switching to other prey species, population-level changes will follow. The Southern Ocean, though oceanographically interconnected, is not a single ecosystem and different areas are dominated by different food webs. Where species occupy different positions in different regional food webs, there is the potential to make predictions about future change scenarios.

The role of notothenioid fish in the food web of the Ross Sea shelf waters: a review, La Mesa, M., Eastman, J. T., Vacchi, M., Polar Biology (2004) 27: 321–338, DOI 10.1007/s00300-004-0599-z.

Abstract: The Ross Sea, a large, high-latitude (72–78 degrees S.) embayment of the Antarctic continental shelf, averages 500 m deep, with troughs to 1,200 m and the shelf break at 700 m. It is covered by pack ice for 9 months of the year. The fish fauna of about 80 species includes primarily 4 families and 53 species of the endemic perciform suborder Notothenioidei. This review focuses on the diet and role in the food web of notothenioids and top-level bird and mammal predators, and also includes new information on the diets of artedidraconids and bathydraconids. Although principally a benthic group, notothenioids have diversified to form an adaptive radiation that includes pelagic and semipelagic species. In the southern Ross Sea, notothenioids dominate the fish fauna at levels of abundance and biomass >90% and are, therefore, inordinately important in the food web. Antarctic krill (Euphausia superba) and mesopelagic fishes are virtually absent from the shelf waters of the Ross Sea. Of the four notothenioid families, nototheniids show the most ecological and dietary diversification, with pelagic, cryopelagic, epibenthic and benthic species. Neutrally buoyant Pleuragramma antarcticum constitutes >90% of both the abundance and biomass of the midwater fish fauna. Most benthic nototheniids are opportunistic and feed on seasonally or locally abundant zooplanktonic prey. Artedidraconids are benthic sit-and-wait predators. Larger bathydraconids are benthic predators on fish while smaller species feed mainly on benthic crustaceans. Channichthyids are less dependent on the bottom for food than other notothenioids. Some species combine benthic and pelagic life styles; others are predominantly pelagic and all consume euphausiids and/or fish. South polar skuas, Antarctic petrels, Adélie and emperor penguins, Weddell seals and minke and killer whales are the higher vertebrate components of the food web, and all prey on notothenioids to some extent. Based on the frequency of occurrence of prey items in the stomachs of fish, bird and mammal predators, P. antarcticum and ice krill E. crystallorophias are the key species in the food web of the Ross Sea. P. antarcticum is a component of the diet of at least 11 species of nototheniid, bathydraconid and channichthyid fish and, at frequencies of occurrence from 71 to 100%, is especially important for Dissostichus mawsoni, vozdarus svetovidovi and some channichthyids. At least 16 species of notothenioids serve as prey for bird and mammal predators, but P. antarcticum is the most important and is a major component of the diet of south polar skua, Adélie and emperor penguins and Weddell seals, at frequencies of occurrence from 26 to 100%. E. crystallorophias is consumed by some nototheniid and channichthyid fish and can be of importance in the diet of emperor and Adélie penguins, although in the latter case, this is dependent on location and time of year.

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A predator’s perspective on causal links between climate change, physical forcing and ecosystem response, Fraser, W.R., Hofmann, E.E., Marine Ecology Progress Series, Vol. 265, 1-15, 2003.

Abstract. The mechanisms by which variability in sea ice cover and its effects on the demography of the Antarctic krill Euphausia superba cascade to other ecosystem components such as apex predators remain poorly understood at all spatial and temporal scales, yet these interactions are essential for understanding causal links between climate change, ecosystem response and resource monitoring and management in the Southern Ocean. To address some of these issues, we examined the long term foraging responses of Adélie penguins Pygoscelis adeliae near Palmer Station, western Antarctic Peninsula, in relation to ice-induced changes in krill recruitment and availability. Our results suggest that (1) there is a direct, causal relationship between variability in ice cover, krill recruitment, prey availability and predator foraging ecology, (2) regional patterns and trends detected in this study are consistent with similar observations in areas as far north as South Georgia, and (3) large scale forcing associated with the Antarctic Circumpolar Wave may be governing ecological interactions between ice, krill and their predators in the western Antarctic Peninsula and Scotia Sea regions. Another implication of our analyses is that during the last 2 decades in particular, krill populations have been sustained by strong age classes that emerge episodically every 4 to 5 years. This raises the possibility that cohort senescence has become an additional ecosystem stressor in an environment where ice conditions conducive to good krill recruitment are deteriorating due to climate warming. In exploring these interactions, our results suggest that at least 1 ‘senescence event’ has already occurred in the western Antarctic Peninsula region, and it accounts for significant coherent decreases in krill abundance, predator populations and predator foraging and breeding performance. We propose that krill longevity should be incorporated into models that seek to identify and understand causal links between climate change, physical forcing and ecosystem response in the western Antarctic Peninsula region.

Abrupt recent shift in d13C and d15N values in Adélie penguin eggshell in Antarctica, Emslie, S.D., Patterson, W.P., Proceedings of the National Academy of Sciences, 104, 11666–11669, 2007.

Abstract. Stable isotope values of carbon (d13C) and nitrogen (d15N) in blood, feathers, eggshell, and bone have been used in seabird studies since the 1980s, providing a valuable source of information on diet, foraging patterns, and migratory behavior in these birds. These techniques can also be applied to fossil material when preservation of bone and other tissues is sufficient. Excavations of abandoned Adélie penguin (Pygoscelis adeliae) colonies in Antarctica often provide well preserved remains of bone, feathers, and eggshell dating from hundreds to thousands of years B.P. Herein we present an 38,000-year time series of d13C and d15N values of Adélie penguin eggshell from abandoned colonies located in three major regions of Antarctica. Results indicate an abrupt shift to lower trophic prey in penguin diets within the past 200 years. We posit that penguins only recently began to rely on krill as a major portion of their diet, in conjunction with the removal of baleen whales and krill-eating seals during the historic whaling era. Our results support the ‘‘krill surplus’’ hypothesis that predicts excess krill availability in the Southern Ocean after this period of exploitation.

Effects of climate variability on the temporal population dynamics of southern fulmars, Jenouvrier, S., Barbraud, C., Weimerskirch, H., Journal of Animal Ecology, Vol. 72, Issue 4, p 576, 12p. July 2003,

Abstract: 1. Ecological and population processes are affected by large-scale climatic fluctuations, and top predators such as seabirds can provide an integrative view on the consequences of environmental variability on ecosystems. Here, we examine the dynamics of a southern fulmar population in Antarctica over a 39-year period and evaluate the impact of environmental variability on the life history traits of this top predator species. 2. Between 1963 and 2002, the number of breeding pairs fluctuated between seven and 53 in relation to variations in sea ice concentration, and increased overall (annual growth rate: 1!0035). Breeding performance tended to be lower in years with low sea ice concentration. The

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proportion of birds attempting to breed varied strongly from one year to the next despite the birds were alive, indicating strong environmental forcing on the decision to breed. The number of new local recruits and immigrants was correlated highly with the number of local breeders, and capture probabilities were positively related to the breeding population size. Local recruitment, number of local breeders and proportion of birds attempting to breed were lower when sea ice concentration during summer was low. 3. Adult survival between 1964 and 2002 was on average 0!923 ± 0!006, and decreased during years with high sea surface temperature and low sea ice concentration. 4. Modelled population growth rate, estimated using matrix models, of the population was 0!9728, a difference of 3!6% compared to the observed rate of increase. This discrepancy is due probably to the immigration rate (3 ± 3%). 5. Demographic parameters were affected by sea ice concentration and sea surface temperature anomalies, probably through an impact on krill availability, the main prey of southern fulmars. During warm anomalies, birds skip breeding probably because the food availability was low and limiting for the highly energy demanding reproductive.

The influence of sea ice on foraging trip duration and Adélie penguin breeding success at Béchervaise Island, Emmerson, L., Clarke, J & Southwell, C., Australian Antarctic Division, Channel Highway, Kingston. Tasmania, 7050 (2007).

Abstract: For some years now, we have been aware of the negative relationship between sea ice extent and breeding success that exists for Adélie penguins (Pygoscelis adeliae) inhabiting Béchervaise Island off the Mawson coast. The last four years have seen a continuation of this trend. These four years have been particularly poor for Adélie penguin reproduction due to extensive sea ice around the colony during the chick rearing period in January. Now that we have more representative data across the full spectrum of possible sea ice conditions we can explore the response of other biological parameters in relation to these ice conditions. One obvious response is the influence of sea ice on foraging trip duration, and how this parameter in turn is likely to influence breeding success. We examine 15 years of foraging trip duration data in relation to sea ice extent around Béchervaise Island to determine what it is about foraging trips that results in chick failure. In conjunction with detailed nest surveys we are able to examine the relationship between foraging trip duration and breeding success at a population level response as well as an individual nest response to determine which factors contribute to nest failure.

Global climate drives southern right whale (Eubalaena australis), Leaper, R., Cooke, J., Trathan, P., Reid, K., Rowntree V., Payne, R., Biology Letters, Royal Society, Vol. 2, No. 2, pp 289-292, June 22, 2006.

Abstract: Sea surface temperature (SST) time-series from the southwest Atlantic and the El Nino 4 region in the western Pacific were compared to an index of annual calving success of the southern right whale (Eubalaena australis) breeding in Argentina. There was a strong relationship between right whale calving output and SST anomalies at South Georgia in the autumn of the previous year and also with mean El Nino 4 SST anomalies delayed by 6 years. These results extend similar observations from other krill predators and show clear linkages between global climate signals and the biological processes affecting whale population dynamics.

D. INVASIVE SPECIES

Biological invasions in the Antarctic: extent, impacts and implications, Frenot, Y., Chown, S.L., Whinam, J., Selkirk, P.M., Convey, P., Skotnicki, M., Bergstrom, D.M., Biological Reviews, Vol. 80, Issue 1, p 45-72, 28p., 2005.

Abstract: Alien microbes, fungi, plants and animals occur on most of the sub-Antarctic islands and some parts of the Antarctic continent. These have arrived over approximately the last two centuries, coincident with human activity in the region. Introduction routes have varied, but are largely associated with

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movement of people and cargo in connection with industrial, national scientific program and tourist operations. The large majority of aliens are European in origin. They have both direct and indirect impacts on the functioning of species-poor Antarctic ecosystems, in particular including substantial loss of local biodiversity and changes to ecosystem processes. With rapid climate change occurring in some parts of Antarctica, elevated numbers of introductions and enhanced success of colonization by aliens are likely, with consequent increases in impacts on ecosystems. Mitigation measures that will substantially reduce the risk of introductions to Antarctica and the sub-Antarctic must focus on reducing propagule loads on humans, and their food, cargo, and transport vessels.

E. OZONE RESEARCH

Boundary layer halogens in coastal Antarctica, Saiz-Lopez, A., Mahajan, A.S., Salmon, R.A., Bauguitte, S.J., Jones, A.E., Roscoe, H.K., Plane, J.M.C., Science, 20, Vol. 317., No. 5836, 348 – 351, July 2007, DOI: 10.1126/science.1141408

Halogens influence the oxidizing capacity of Earth's troposphere, and iodine oxides form ultrafine aerosols, which may have an impact on climate. We report year-round measurements of boundary layer iodine oxide and bromine oxide at the near-coastal site of Halley Station, Antarctica. Surprisingly, both species are present throughout the sunlit period and exhibit similar seasonal cycles and concentrations. The springtime peak of iodine oxide (20 parts per trillion) is the highest concentration recorded anywhere in the atmosphere. These levels of halogens cause substantial ozone depletion, as well as the rapid oxidation of dimethyl sulfide and mercury in the Antarctic boundary layer.

An Ecosystem Perspective on UV Radiation and Climate Change Impacts, Fraser,W., Karentz, D., Antarctic Update, USGCRP Seminar, 1997. http://www.usgcrp.gov/usgcrp/seminars/9762DD.html

Abstract: Dr. Fraser and Dr. Karentz have concluded the following regarding the impacts of ozone depletion and climate change in the Antarctic: 1) Changing patterns of snow deposition and melt are affecting summer nesting habitats of penguins in the West Antarctic peninsula by producing a mismatch between the availability of breeding habitat and the requirements of penguins at various stages in their breeding cycle; 2) these changes are consistent with there having been warming in certain regions of the West Antarctic on the order of 4-5C, which are values generally consistent with observations and model predictions; 3) those Antarctic species found at the periphery of their breeding ranges are most likely to undergo pronounced changes due to climate change; 4) Antarctic marine organisms have different sensitivities to UV exposure; 5) the amount of biological damage to Antarctic marine organisms due to UV-B radiation is directly correlated to the level of ozone depletion; 6) increased levels of UV-B radiation in the Antarctic can, and do, result in impairment of metabolic processes, decreases in growth, reduction in reproductive potential, morphological abnormalities, genetic damage, and death; and 7) UV-induced damage to marine organisms can further lead to the disruption of entire ecosystems and food webs, therefore, the availability of food resources for humans and other ecosystems.

Influence of ozone-related increases in ultraviolet radiation on Antarctic marine organisms, Karentz, D., and Bosch, I., American Zoologist, Vol. 41, pp. 3–16, 2001.

Abstract: Every spring for the past two decades, depletion of stratospheric ozone has caused increases in ultraviolet B radiation (UVB, 280–320 nm) reaching Antarctic terrestrial and aquatic habitats. Research efforts to evaluate the impact of this phenomenon have focused on phytoplankton under the assumption that ecosystem effects will most likely originate through reductions in primary productivity; however, phytoplankton do not represent the only significant component in ecosystem response to elevated UVB. Antarctic bacterioplankton are adversely affected by UVB exposure; and invertebrates and fish, particularly early developmental stages that reside in the plankton, are sensitive to UVB. There is little information available on UV responses of larger Antarctic marine animals (e.g., birds, seals and

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whales). Understanding the balance between direct biological damage and species-specific potentials for UV tolerance (protection and recovery) relative to trophic dynamics and biogeochemical cycling is a crucial factor in evaluating the overall impact of ozone depletion. After more than a decade of research, much information has been gathered about UV-photobiology in Antarctica; however, a definitive quantitative assessment of the effect of ozone depletion on the Antarctic ecosystem still eludes us. It is only obvious that ozone depletion has not had a catastrophic effect in the Antarctic region. The long-term consequences of possible subtle shifts in species composition and trophic interactions are still uncertain.

Increased exposure of Southern Ocean phytoplankton to ultraviolet radiation, Lubin, D., Arrigo, K., van Dijken, G., Geophysical Research Letters, Vol. 31, L09304, doi:10.1029/2004GL019633, 2004.

Abstract: Satellite remote sensing of both surface solar ultraviolet radiation (UVR) and chlorophyll over two decades shows that biologically significant ultraviolet radiation increases began to occur over the Southern Ocean three years before the ozone “hole” was discovered. Beginning in October 1983, the most frequent occurrences of enhanced UVR over phytoplankton-rich waters occurred in the Weddell Sea and Indian Ocean sectors of the Southern Ocean, impacting 60% of the surface biomass by the late 1990s. These results suggest two reasons why more serious impacts to the base of the marine food web may not have been detected by field experiments: (1) the onset of UVR increases several years before dedicated field work began may have impacted the most sensitive organisms long before such damage could be detected, and (2) most biological field work has so far not taken place in Antarctic waters most extensively subjected to enhanced UVR.