The State of the Ocean report 2013

Summary

Climate change and the ocean – What does the future hold?

• Jelle Bijma, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
• Hans-O. Pörtner, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
• Chris Yesson, Institute of Zoology, Zoological Society of London, UK
• Alex D. Rogers, Department of Zoology, University of Oxford, Oxford UK

Number of citations: 13

We have been taking the ocean for granted. It has been shielding us from the worst effects of accelerating climate change by absorbing excess CO₂ from the atmosphere, and this has created a ‘deadly trio’ of impacts – acidification, warming and deoxygenation – which are combining to dramatic effect on the flora and fauna of the ocean and exacerbating the effects of other factors such as pollution, eutrophication and overfishing. According to a flood of recent literature, most, if not all, of the Earth’s five past mass-extinction events have involved at least one of these three symptoms of global carbon perturbations; all are present in the ocean today.

More worrying still, the scale and rate of the present day carbon perturbation and resulting ocean acidification is unprecedented in Earth’s known history. Today’s rate of carbon release, at approximately 30 Gt of CO₂ per year, is at least 10 times faster than that which preceded the last major species extinction (the Paleocene Eocene Thermal Maximum extinction, or PETM, ca. 55 million years ago), while geological records indicate that the current acidification is unparalleled in at least the last 300 million years. We are entering an unknown territory of marine ecosystem change, and exposing organisms to intolerable evolutionary pressure. The next mass extinction event may have already begun.

Developed, industrialised human society is living above the carrying capacity of the Earth, and the
implications for the ocean, and thus for all humans, are huge. It is now certain that the uptake of CO₂ into the ocean is outstripping its capacity to absorb it, resulting in a reduction in ocean pH (i.e. an
increase in acidity) coupled with a lowering of its CO₂ buffering capacity. Acidification is causing a substantial decline in carbonate ion concentrations and resulting in 800km² of the seafloor becoming exposed to waters that are unsaturated with respect to aragonite every year. The rate of acidification is 50% faster at high latitudes compared to sub-tropical waters because of the effects of temperature on ocean chemistry. Biological impacts are already being observed as acidification is a direct threat to all marine organisms that build their skeletons out of calcium carbonate, including reef-forming corals, crustaceans, molluscs and other planktonic species that are at the lower levels of pelagic food webs. If current levels of CO₂ release continue we can expect extremely serious consequences for ocean life; at CO₂ concentrations of 450–500 ppm (projected in 2030–2050), erosion will exceed calcification in the coral reef building process, resulting in the extinction of some species and a decline in biodiversity overall.

The second prong in the ‘deadly trio’ is ocean warming. The average temperature of the upper layers of the ocean has increased by 0.6^oC over the last 100 years, with direct and well-documented physical and biogeochemical consequences. The impacts that continued warming is projected to have in the decades to 2050 include: reduced seasonal ice zones, including the disappearance of Arctic summer sea ice; increasing stratification of ocean layers, leading to oxygen depletion; increased venting of the GHG methane from the Arctic seabed; increased incidence of anoxic and hypoxic (low oxygen) events.

The biological implications encompass: sea temperature-driven range shifts and species invasions, in particular a projected movement poleward of 30–130 km, and 3.5m deeper, by marine fish each decade; loss of 60% of present biodiversity of exploited marine fish and invertebrates, including numerous local extinctions; increased disease prevalence as a result of pathogen range expansions; increased extinctions, with ice-dependent polar species such as seals and penguins at greatest risk; mass coral bleaching leading to increased coral reef mortality and a predicted phase shift from coral domination to algal domination in the Great Barrier Reef and Caribbean reefs. The synergistic effect of acidification and warming are considered likely to lead to rapid and terminal decline of tropical coral reefs by 2050. All these changes will have massive economic and food security consequences, not least for the fishing industry and all those who depend on it. It is predicted that the redistribution of commercial fish species through range shifts will lead to a 40% decrease in catch potential in the tropics by 2050, and 30–70% increase in the high-latitude zones – where richer societies and more industrialised fisheries are located.

To complete the triumvirate, there is deoxygenation: the accumulating evidence that the oxygen inventory of the ocean is progressively declining. Predictions for ocean oxygen content suggest a decline of between 1% and 7% by 2100. This is occurring in two ways: the broad trend of decreasing oxygen levels in tropical oceans and areas of the North Pacific over the last 50 years and the dramatic increase in coastal hypoxia associated with eutrophication. The former is caused by global warming, the second by increased nutrient runoff from agriculture and sewage. Impacts of the broad deoxygenation on marine species and ecosystems are varied, but include habitat compression for large ocean predators such as marlin, which have a high oxygen demand; this is likely to increase the vulnerability of these large fish, which also include tuna species, to fishing pressure. Another symptom of climate change has been the incursion of anoxic (no oxygen) waters into the inner shelf adjacent to the upwelling zone along the west coast of North America, with such events occurring in 2006, 2007 and 2008 having negative effects and causing mortalities among marine fauna.

Oxygen-depleted, or hypoxic, zones have spread since the introduction of industrial fertilizers in the 1940s, and since the 1960s the number of ‘dead zones’ has doubled every 10 years, concentrated in areas near human population centres and large water sheds. Inland seas and estuaries – including the Black Sea, the Kattegat, and Chesapeake Bay – are particularly badly affected, and the number of hypoxic zones is thought to be underestimated as their occurrence is not reported in many geographic zones. Over long periods of time, hypoxia or anoxia will eliminate most benthic fauna within areas vulnerable to the formation of dead zones, causing ecosystems to become dominated by microorganisms (some of them pathogenic) and harmful algal blooms. Climate-induced and eutrophication-induced hypoxia may interact as elevated temperatures enhance stratification and may increase the likelihood of eutrophication-induced coastal hypoxia.

It is the simultaneous occurrence of the ‘deadly trio’ that is seriously effecting how productive and efficient the ocean is, as temperatures, chemistry, surface stratification, nutrient and oxygen supply are all implicated, meaning that many organisms will find themselves in unsuitable environments. These impacts will have cascading consequences for marine biology, including altered food web dynamics and the expansion of pathogens. To make matters even worse, this is all happening to marine ecosystems already undermined by other human pressures such as overfishing, eutrophication and pollution. The adaption of species to these altered conditions is in some cases possible, as is migration, though as warming demands a poleward migration while acidification encourages the movement to warmer more equatorial waters, the ‘green pastures’ will become increasingly scarce and competition for them fierce. Mass extinctions happen in the geological equivalent of overnight; we may already have entered into an extinction period and not yet realised it. What is certain is that current carbon perturbations will have huge implications for humans, and may well be the most important challenge faced since the first hominids evolved. The urgent need to reduce the pressure of all ocean stressors, especially CO₂ emissions, is well signposted.

Summary

Fisheries – Hope or despair?

• Tony J. Pitcher, Fisheries Centre, University of British Columbia, British Columbia, Canada
• William W.L. Cheung, Fisheries Centre, University of British Columbia, British Columbia, Canada

Number of citations: 16

We have drawn heavily from the ocean to feed millions of people over the millennia, but have the last decades of increasingly intense and industrialised fishing done irreversible harm to its biodiversity?

For the past 10 years, fisheries worldwide have been generally reported as being in an extremely poor state with no improvement in sight and forecasts warning of the collapse of ocean fisheries as we know them. However, more recently, some studies have suggested that fisheries depletions have turned the corner, that things may have always been better than we thought and are now improving. Sadly, the authors of this review for IPSO conclude that this optimistic outlook is misplaced, largely because the analysis it is founded on was primarily based on evidence from better-managed, developing world fisheries. Deeper analysis of the status of the majority of world fisheries instead confirms the previous dismal outlook: serious depletions are the norm, management quality is poor, and catch per unit effort continues to decline.

The global picture for further fisheries species extinctions, the degradation of food webs and seafood security is alarming and the depressingly poor quality of fishing management is one key issue that challenges any claim that things have improved. A recent global assessment of compliance with Article 7 (fishery management) of the 1995 FAO Code of Conduct for Responsible Fisheries, awarded 60% of countries a “fail” grade and saw no country identified as being overall “good”. Some of the worst compliance results were related to catch issues that should be straightforward to address, such as tackling bycatch, discard and the scourge of “ghost fishing” by lost fishing gear. All were awarded “fail” scores worldwide and remain hugely destructive problems. The Indian Ocean and the Mediterranean scored worst of all.

There has been widespread failure among the principal fishing countries to adopt the key features of ecosystem-based fishery management, and “silver bullet” approaches that rely heavily on one type of management solution (e.g. property rights, or marine protected areas) have been shown to be of only limited use. While there are some promising signs that the management of some fisheries in the developed world is improving, over 80% of the world’s fish are caught elsewhere, in many cases in fisheries where stocks are not assessed. The analysis suggesting that fisheries status is improving was based on just 16% of world fisheries, mostly in Europe and North America. More recent, global analysis suggests that catch per effort is declining and in 2012 FAO determined that 70% of world fish populations are overexploited of which 30% have biomass collapsed to less than 10% of unfished levels. Meanwhile illegal, unregulated and unreported (IUU) fishing remains a huge problem; the total extent of IUU fishing is uncertain but estimated to be at least 35% of the global catch. This phenomenon is related to another trend which is the dark side of improved fisheries management and control in the developed world; there has been an often uncontrolled redistribution of effort into poorer regions, causing serious overexploitation and the unethical sequestering of local benefits – including valuable sources of food – and biodiversity.

Some fisheries scientists warn that we are living through a major catastrophe in our exploitation of fish stocks and regard most of the management that is taking place to be working to support a globalised commercial enterprise marketing commoditised fish, at the expense of biodiversity and conservation, as well as long term food security. In most parts of the world there is very little science-based action to conserve the non-fished components of the ecosystem, whether top predators or low trophic level groups. Even where many fisheries are assessed, as in the developed world, there is almost no explicit inclusion of these non-fishing factors. Compounding this already dire situation, climate change is expected to continue to cause range shifts in important commercial species, reduce the actual body size of fishes, and make management more challenging and unpredictable. While there are still gaps in our understanding of climate change effects on fisheries, there is already sufficient scientific information highlighting the urgent need to implement mitigation and adaptation policies to minimise the impacts.

A fundamental solution to many of these problems is to ensure effective implementation of community- and ecosystem-based management, favouring small-scale fisheries. Examples of broad-scale measures include introducing true co-management with resource adjacent communities, eliminating harmful subsidies that drive overcapacity, protection of vulnerable marine ecosystems, banning the most destructive fishing gear, and combating IUU fishing. The challenge is to effectively and ethically implement these solutions and this requires effort and cooperation at all levels from small communities to international bodies. There are examples that indicate that declining trends can be reversed but action needs to be urgent, focused, innovative and global if we are to avoid tipping us further, and irreversibly, onto the despair side of the hope/despair balance.

Summary

Evaluating legacy contaminants and emerging chemicals in marine environments

• Thomas H. Hutchinson, Centre for Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Dorset, UK
• Brett P. Lyons, Centre for Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Dorset, UK
• John E. Thain, Centre for Environment, Fisheries and Aquaculture Science, Weymouth Laboratory, Dorset, UK
• Robin J. Law, Centre for Environment, Fisheries and Aquaculture Science, Suffolk, UK

Number of citations: 10

Complex mixtures – or ‘cocktails’ – of ‘legacy’ contaminants (that are now subject to control, such as heavy metals and persistent organic pollutants), emerging chemicals (defined as chemicals that have been detected in the environment, but are currently unregulated, the fate and biological impacts of which are poorly understood) and natural chemicals (e.g. algal biotoxins) in marine ecosystems pose a threat to human health via the food chain, and represent important scientific, economic and health challenges. Protecting marine ecosystems and seafood resources from the adverse effects of chemical contaminants therefore remains an important issue.

Analytical chemistry plays a key role in evaluating to what extent regulatory steps (such as regional conventions controlling certain persistent, bioaccumulative and toxic, or PBT, chemicals) have been effective in leading to reduced emissions of these legacy contaminants into marine environments. Evidence suggests that a number of these regional conventions succeeded in reducing inputs and levels of certain PBT legacy contaminants in many areas, although problematic exposure scenarios do still exist, for example lingering high levels of polycyclic aromatic hydrocarbons (PAH) in UK estuaries. In parallel, the application of biomarkers and bioassays integrated with analytical chemistry has strengthened the evidence base to support an ecosystem approach to manage marine pollution problems. In recent years, however, the increased sensitivity of analytical chemistry, toxicity alerts and wider environmental awareness has led to a focus on emerging chemical contaminants (including brominated flame retardants, microplastics, nanomaterials and recreational drugs). High profile recent examples – such as the Prestige and Deepwater Horizon oil disasters in Spain and the US, and the ongoing pollution of the Pearl River estuary in China – have also highlighted the huge damage and cost that marine pollution can incur and helped focus public and political attention on the issue.

The challenges posed by chemical contamination and pollution can be met by initiating a programme of exposure assessments for priority chemicals, to establish a better understanding of the biological effects of these chemicals and to better understand the impacts of complex mixtures of substances on physiology. The economic and infrastructural challenges posed by such a wide variety of chemicals means that a targeted, effects-based strategy is needed.

In order to meet these challenges, and pursue cost-effective scientific approaches that can provide the evidence necessary to support policy needs, the authors of this paper support the widely held view that, rather than increasing the analytical chemistry monitoring of large numbers of emerging contaminants, it will be important to target key groups of chemicals of concern using effects-directed analysis. It is also important to evaluate to what extent existing biomarkers and bioassays can address various classes of emerging chemicals using the adverse outcome pathway (AOP) approach now being developed by the Organization for Economic Cooperation and Development (OECD) with respect to human toxicology and ecotoxicology. These methods promise to be valuable tools for determining the most effective way to address complex chemical contamination mixtures that can threaten marine ecosystems and seafood resources.

Summary

Climate change impacts on coral reefs: Synergies with local effects, possibilities for acclimation, and management implications

• Mebrahtu Ateweberhan, Department of Life Science, University of Warwick, UK
• David A. Feary, School of the Environment, University of Technology, Sydney, Australia
• Shashank Keshavmurthy, Biodiversity Research Centre, Academia Sinica, Taipei, Taiwan, Province of China
• Allen Chen, Biodiversity Research Centre, Academia Sinica, Taipei, Taiwan, Province of China
• Michael H. Schleyer, Oceanographic Research Institute, Durban, South Africa
• Charles R.C. Sheppard, Department of Life Science, University of Warwick, UK

Number of citations: 13

Corals reefs are one of the most vulnerable ecosystems to climate change impacts, in particular to acidification and warming and the synergy between them. These factors also interact with local pressures from pollution, overfishing and shoreline alterations to further reduce the resilience of coral reefs and amplify the effects of climate change. This is a particular concern as a substantial number of the world’s poorest people depend on coral reefs, including for reef-supplied food. Prior to the major warming-induced coral bleaching event of 1998, local factors such as nutrient run-off and destructive fishing practices were seen as the greatest threat to corals; since 1998 – when some of the most remote reefs, previously considered at low risk, were worst affected – the attention has shifted to climate change, but it is vital that the interaction between all factors is considered when making management decisions.

Coral bleaching follows anomalously high seawater temperatures, and such episodes have been increasing steadily over the past three decades in terms of both frequency and intensity. Ocean acidification is another direct threat to corals as increased bi-carbonate coupled with reduced calcium carbonate (a result of acidification) drastically reduces the growth of coral skeletons and eventually will dissolve existing calcified matter. Acidification has also been identified by some researchers as a trigger for coral bleaching and can slow down post-bleaching recovery. The ocean is already on average 0.1 pH units more acidic than in the pre-industrial period and this reduction in pH is expected to reach 0.4 pH units more acidic by 2100. At 450ppm CO₂e (associated with a 2^oC temperature rise) coral reefs will cease to grow, at 560ppm CO₂e (approx. 3^oC rise) they may start to dissolve. The response of corals to acidification may also be synergistic with other factors, notably temperature, to multiply and amplify effects. Interaction between coral bleaching, acidification and diseases are expected to negatively influence coral survival, growth, reproduction, larval development and species development.

The authors of this paper consider it unlikely that coral reefs can adapt or acclimatise to these fast changing environmental conditions, i.e. decadal rather than millennial rates of climate change. Responses to increasing episodic mass bleaching and mortality events that have already occurred indicate that adaptation is not happening fast enough to match the rate and frequency of warming events and hope that species will acclimatise appears to be misplaced. However, some species are more affected than others leading to fundamental changes in the composition of reef communities. In many coral reefs suffering from degradation, the structure of seabed ecosystems is already characterised by low coral cover and diversity and the dominance of seaweed, algae and soft-bodied invertebrates. It is vital that local efforts to reduce the impact of direct stressors such as pollution and fishing and aid reef recovery, are stepped-up. It is tempting to consider such local initiatives futile in the face of rising CO₂ levels, but evidence shows that reefs that have fewer local pressures (such as in the Chagos atolls) recover better from high temperatures than those where there are many additional pressures (such as in the Seychelles). This presents a strong incentive for local action to boost the resilience of coral reefs to global stressors.

At the global management level, the key message is that the current targets for carbon emission reductions are unrealistic in terms of ensuring coral reef survival, especially as there is a time lag of several decades between atmospheric CO₂ and levels of CO₂ dissolved in the ocean – a factor that appears to be beyond the grasp of most policy-makers. Put simply, the target to limit temperature rise to 2^oC, or remain below 450 CO₂e, is not sufficient for coral reefs to survive. Lower targets should be urgently pursued. Even more worrying, some socio-economic evaluations conclude that even the 2^oC target is too hard to bear and are encouraging settling for a 650ppm CO₂e stabilisation level. This “easy” economic compromise would be completely fatal for coral reefs. It is imperative that targets below 450 ppm CO₂e be agreed and implemented, combined with coordinated programmes at local and regional levels to reduce local stress factors and boost resilience. Without such dedicated action it is predicted that most reefs will be lost as effective, productive systems within a few decades.

Summary

Ocean in peril: Reforming the management of global ocean living resources in areas beyond national jurisdiction

• Kristina M. Gjerde, IUCN Global Marine and Polar Program, Massachusetts, USA
• Duncan Currie, Globelaw, Christchurch, New Zealand
• Kateryna Wowk, NOAA, Washington, USA
• Karen Sack, The Pew Charitable Trusts, Washington, USA

Number of citations: 6

The existing legal and institutional framework for governing and managing the resources of the high seas (the vast areas of the ocean that are not included in the exclusive economic zone, EEZ, or under the national jurisdiction of any state) is weak and poorly implemented. As a result, high seas living resources are not being used sustainably and the health of the marine environment is being compromised. The high seas is often referred to as the ‘the global ocean commons’, a common heritage of humankind but its biodiversity is exploited predominantly by vessels from developed States and it is also subject to global problems related to climate change, pollution and large-scale human activities such as shipping.

The previous paper has already shown that global fisheries as a whole are in crisis; many fish stocks caught largely in the high seas, including one third of highly-migratory tuna and more than half of oceanic sharks, are overexploited or depleted. It has also been estimated that up to half of all illegal fish catches, in terms of value, take place in the high seas. Chronic mismanagement by regional fisheries management organisations (RFMOs), combined with excessive government subsidies spurring overcapacity in open-access fisheries, contribute to overfishing and IUU fishing in the high seas. The consequences are brought into stark relief by the recent collapse of the once highly productive jack mackerel fishery in the South Pacific in less than 20 years. While governments negotiated the creation of an RFMO in the region, and deliberated over interim measures, a ‘race to fish’ before the agreement entered into force drove stocks from 30 million tons to just 3 million.

RFMOs are the institutions legally charged with managing high seas fisheries under UNCLOS, yet a recent assessment identified that 67% of stocks (for which the status is known) under the jurisdiction of the 18 existing RFMOs are depleted or being overfished. A major problem is that the rules and decisions adopted by each RFMO apply only to its own member States while vessels owned by other States are able to fish in the region. Nearly all RFMOs are comprised primarily of States with a direct economic interest in the fishery, with delegates representing commercial fishing interests hugely outnumbering those geared towards ecological concerns. There is also a wide discrepancy between the effectiveness of different RFMOs – indicating what can be achieved where political will and pressure exist. For example, the Commission for the Conservation of Antarctic Living Marine Resources (CCAMLR) is widely praised, while the International Commission for the Conservation of Atlantic Tunas (ICCAT) has been labeled an international disgrace. At best, the pace of reform has been slow and uneven.

IUU fishing is a global phenomenon and an area where the advantages of an integrated global approach are already acknowledged. Persistent IUU fishing today is to a large extent due to the traditional reliance on flag States to enforce regionally agreed measures – based on the legal fiction that a ship is a floating piece of a nation’s territory. This allows certain irresponsible States to evade their commitments, and encourages the practice of reflagging ships to evade enforcement action. The 2009 FAO Port State Measures Agreement sets the stage for a consistent international standard to replace ad hoc regional approaches but much more needs to be done to achieve compliance and enforcement. At the moment, illegal fishers remain too confident in their ability to escape detection and punishment. Marine living resources crime, in particular illegal fishing, needs to be integrated into wider efforts to suppress the other transnational crimes to which it can be connected, such as piracy, drug trafficking, terrorism and the illegal trafficking of people and weapons. The existing regional and international policing community, particularly INTERPOL and EUROPOL, should become more engaged in this issue and help implement measures to shift IUU fishing from a low risk, high reward activity to one that has high risks with few chances for rewards.

The technology needed to implement effective monitoring, control and surveillance of fishing activities in the oceans already exists, which means that the ongoing inability to manage fisheries on the high seas comes down to gaps in governance and the ineffectiveness of the organisations charged with managing such fisheries, i.e. RFMOs. The authors of this paper warn that if no change is made, the deterioration of the high seas will accelerate as more areas are targeted for fishing or other extractive activities. This may weaken ecosystem function, resilience and adaptive capacity and thereby exacerbate the effects of other marine stressors, such as warming and acidification. They therefore outline three possible avenues for: 1) a ‘soft’ change through a series of UN General Assembly Resolutions, which is deemed insufficient as such resolutions often produce few practical results, can take years to negotiate and would still leave RFMOs as the primary institutions; 2) an enhanced regional approach focused on strengthening RFMO performance and capacity for ecosystem based management of living resources, which has the disadvantage of continuing with the regional ‘silo’ approach and not introducing any globally agreed goals; and 3) an ambitious fundamental reform which would combine the two previous proposals with a global infrastructure to coordinate, ensure consistency and supervise, sanction and enforce the necessary changes.

The key elements of this enhanced global infrastructure for high seas governance could include the establishment of a global high seas enforcement agency to provide integrated and coordinated monitoring and enforcement for the full range of ocean security threats. Most importantly, the fundamental linchpin proposed is a new implementing agreement for the conservation and sustainable use of biodiversity in areas beyond national jurisdiction under the auspices of UNCLOS.

The current system of high seas governance that tolerates the mismanagement and misappropriation of high seas living resources is placing our ocean in peril. It is time for a new paradigm that promotes ocean health, resilience and integrity, to secure the well-being, diversity and productivity of the ocean for the benefit of present and future generations.

All five of these papers, and the report arising from the two seminal IPSO meetings, outline some of the most important steps that need to be taken to achieve a more holistic, ecosystem-based approach to marine management. Ultimately, however, this must be undertaken within a wider re-evaluation of the core values of human society and its relationship to the natural world on which we all rely. The future of humanity and the future of the ocean are intertwined.