Potential Impacts of Climate Change on California’s Fish and Fisheries

In California much work is being done at the local and state levels to mitigate the effects of climate change, and develop adaptation strategies. In particular, California recently released for public comment “Safeguarding California: Reducing Climate Risk” – an update to the 2009 California Climate Adaptation Assessment. In it, decision makers specifically highlight the need to improve understanding of climate risks to biodiversity and habitat, among other recommendations.

This report reviews aspects of the latest scientific literature on the potential impacts of climate change on California’s fish and fisheries. It provides a general overview of possible impacts on upwelling and primary ocean productivity, and information on how ocean temperature, stratification, and changes in wind and currents may affect the distribution and range and productivity of fish species of commercial and recreational value.

Led by Ocean Protection Council Science Advisory Team (OPC-SAT) member Dr. Bill Sydeman of the Farallon Institute, this report provides valuable information on the state of the science of the risks posed by climate change to California’s marine ecosystems and fisheries. While not designed as a vulnerability assessment for individual species, this report lays the necessary groundwork for such an investigation in the future.

Gulf of Mexico: Ocean Acidification

What is ocean acidification? Every day, the ocean absorbs approximately one-third of the carbon dioxide we put into the atmosphere when we burn fossil fuels and clear land. When carbon dioxide dissolves in seawater, it becomes an acid. This acid is lowering the pH of ocean water. pH is an important vital sign of ocean health, and its rapid change raises a red fl ag. Scientists refer to this shift in ocean chemistry as ocean acidifi cation.

How fast is ocean chemistry changing? Ocean acidifi cation is happening faster than it has in the past 300 million years, catapult- ing us into unknown territory. Since the Industrial Revolution, the world’s oceans have become 30 percent more acidic, on average. Scientists predict the acidity of our oceans could double or triple by the end of the century compared to preindustrial times.

How might ocean acidification affect marine life? As seas become more acidic, they become inhospitable to some sea life. Rising acidity robs seawater of carbonate ions, an essential ingredient used by creatures like shellfi sh and corals to build their shells. In slightly more acidic water, they must expend more energy to build shells, which may leave them less able to fi nd food or reproduce. On the extreme end, if seawater becomes acidic enough, shells literally dissolve, which can be disastrous for survival.

Will all sea life be negatively affected? Not all ocean organisms will be harmed by ocean acidifi cation. We know that some creatures—corals, clams, oysters, scallops, and some forms of plankton—are sensitive to these chemical changes. More research is needed to fully understand how declines in sensitive species could ripple across the food web and cause harm to commercial finfish.

Ocean Acidification and Alaska Fisheries: Views and Voices of Alaska’s Fishermen, Marine Industries and Coastal Residents

In winter 2011-2012 the Alaska Marine Conservation Council (AMCC) sponsored community roundtable discussions on ocean acidification and Alaska fisheries in the fisheries-dependent communities of Homer, Kodiak and Dillingham in southern Alaska.

The roundtables were designed to engage coastal Alaskans and members of the Alaska seafood industry whose lives and local economies will be affected by changes linked to ocean acidification (OA). Specifically, the roundtables were intended to accomplish three inter-related goals: 1) bring together the efforts and expertise of scientists, subsistence harvesters, commercial fishermen, natural resources managers and coastal residents to better assess and address the impacts of OA on local fisheries and livelihoods; 2) develop ideas and advance dialogue concerning the needs and potential contributions of fishermen and fishing communities in responding to the threat posed by OA; and 3) provide insight into how the fishing industry might engage in policy action related to OA in the future.

NOAA Fisheries Climate Science Strategy

The oceans are dynamic systems. That’s why striking the right balance between use and protection of marine and coastal resources has always been a complicated process, whether its setting fishing levels, reducing by-catch, recovering endangered species, or considering permits for oil and gas exploration. Incorporating climate change into decision-making makes these efforts more challenging than ever before. Increased information, tools and action are essential to meeting these challenges.

This NOAA Fisheries Climate Science Strategy (Strategy) was developed to meet the growing demand for information to better prepare for and respond to climate-related impacts on the nation’s living marine resources and resource-dependent communities. The Strategy is part of a proactive approach to increase the production, delivery and use of climate-related information to fulfill NOAA Fisheries mandates in a changing climate. Implementing this Strategy will help reduce impacts and increase the resilience of our valuable living marine resources, and the people, businesses and communities that depend on them.

Impacts of climate change on marine ecosystem production in societies dependent on fisheries

Growing human populations and changing dietary preferences are increasing global demands for fish1 concerns over fisheries sustainability2. Here we develop and link models of physical, biological and human responses to climate change in 67 marine national exclusive economic zones, which yield approximately 60% of global fish catches, to project climate change yield impacts in countries with di!erent dependencies onmarine fisheries3. Predicted changes in fish production indicate increased productivity at high latitudes and decreased productivity at low/mid latitudes, with considerable regional variations. With few exceptions, increases and decreases in fish production potential by 2050 are estimated to be <10% (mean +3.4%) from present yields. Among the nations showing a high dependency on fisheries3, climate change is predicted to increase productive potential in West Africa and decrease it in South and Southeast Asia. Despite projected human population increases and assuming that per capita fish consumption rates will be maintained1 ongoing technological development in the aquaculture industry suggests that projected global fish demands in 2050 could be met, thus challenging existing predictions of inevitable shortfalls in fish supply by the mid-twenty-first century4. This conclusion, however, is contingent on successful im- plementation of strategies for sustainable harvesting and e!ective distribution of wild fish products from nations and regions with a surplus to those with a deficit. Changes in management e!ectiveness2 and trade practices5 will remain the main influence on realized gains or losses in global fish production.

Marine climate change impacts: Report Card 2013

The 2013 MCCIP Report Card provides the very latest updates on our understanding of how climate change is affecting UK seas. Over 150 scientists from more than 50 leading science organisations contributed to this report card covering a wide range of topics ensuring that the information is timely, accurate and comprehensive. The key messages provided by this Report Card are summarised below:

  • Temperature records continue to show an overall upward trend despite short-term variability. For example, in the last decade, the average UK coastal sea-surface temperature was actually lower in 2008-2012 than in 2003-2007.
  • The seven lowest Arctic sea-ice extents in the satellite era were recorded between 2007 and 2013. The continuing downward trend is providing opportunities for the use of polar transit routes between Europe and Asia by commercial ships.
  • Changes to primary production are expected throughout the UK, with southern regions (e.g. Celtic Sea, English Channel) becoming up to 10% more productive and northern regions (e.g. central and northern North Sea) up to 20% less productive; with clear implications for fisheries.
  • There continue to be some challenges in identifying impacts of climate change. These are due to difficulties distinguishing between short-term variability and long-term trends, and between climate drivers and other pressures.

Climate Change: Implications for Fisheries & Aquaculture

The Fifth Assessment Report from the Intergovernmental Panel on Climate Change is the most comprehensive and relevant analysis of our changing climate. It provides the scientific fact base that will be used around the world to formulate climate policies in the coming years. This document is one of a series synthesizing the most pertinent findings of AR5 for specific economic and business sectors. It was born of the belief that the fisheries & aquaculture sector could make more use of AR5, which is long and highly technical, if it were distilled into an accurate, accessible, timely, relevant and readable summary.

Projected impacts of climate change on marine fish and fisheries

This paper reviews current literature on the projected effects of climate change on marine fish and shellfish, their fisheries, and fishery-dependent communities throughout the northern hemisphere. The review addresses the following issues: (i) expected impacts on ecosystem productivity and habitat quantity and quality; (ii) impacts of changes in production and habitat on marine fish and shellfish species including effects on the community species composition, spatial distributions, interactions, and vital rates of fish and shellfish; (iii) impacts on fisheries and their associated communities; (iv) implications for food security and associated changes; and (v) uncertainty and modelling skill assessment. Climate change will impact fish and shellfish, their fisheries, and fishery-dependent communities through a complex suite of linked processes. Integrated interdisciplinary research teams are forming in many regions to project these complex responses. National and international marine research organizations serve a key role in the coordination and integration of research to accelerate the production of projections of the effects of climate change on marine ecosystems and to move towards a future where relative impacts by region could be compared on a hemispheric or global level. Eight research foci were identified that will improve the projections of climate impacts on fish, fisheries, and fishery-dependent communities.

Guidelines for incorporating fish distribution shifts into a fisheries management context

The impacts of climate change have been demonstrated to influence fisheries resources. One way climate has affected fish stocks is via persistent shifts in spatio-temporal distribution. Although examples of climate-forced distribution shifts abound, it is unclear how these shifts are practically accounted for in the management of fish stocks. In particular, how can we take into account shifting stock distribution in the context of stock assessments and their management outputs? Here, we discuss examples of the types of fish stock distribution shifts that can occur. We then propose a decision tree framework of how shifting stock distributions can be addressed. Generally, the approaches for addressing such shifts fall into one of three main alternatives: re-evaluate stock identification, re-evaluate a stock unit area, or implement spatially explicit modelling. We conclude by asserting that the approach recommended here is feasible with existing information and as such fisheries managers should be able to begin addressing the role of changes in stock distribution in these fish stocks. The implications of not doing so could be notably undesirable.

Climate change implications for fisheries and aquaculture: Overview of current scientific knowledge

An overview of the current scientific knowledge available on climate change implications for fisheries and aquaculture is provided through three technical papers that were presented and discussed during the Expert Workshop on Climate Change Implications for Fisheries and Aquaculture (Rome, 7–9 April 2008). A summary of the workshop outcomes as well as key messages on impacts of climate change on aquatic ecosystems and on fisheries- and aquaculture-based livelihoods are provided in the introduction of this Technical Paper. The first paper reviews the physical and ecological impacts of climate change relevant to marine and inland capture fisheries and aquaculture. The second paper tackles the consequences of climate change impacts on fisheries and their dependent communities. Finally, the third paper addresses the impacts of climate change on aquaculture.