Chris Harrod on the Impact of Climate Change in Fish Communities

Emerging Research Fronts Commentary, December 2011


Article: Implications of climate change for the fishes of the British Isles

Authors: Graham, CT;Harrod, C
Journal: J FISH BIOL, 74 (6): 1143-1205, APR 2009
Addresses: Queens Univ Belfast, Sch Biol Sci, Ctr Med Biol, 97 Lisburn Rd, Belfast BT9 7BL, Antrim, North Ireland.
Queens Univ Belfast, Sch Biol Sci, Ctr Med Biol, Belfast BT9 7BL, Antrim, North Ireland.\nUniv Coll Cork, Dept Zool Ecol & Plant Sci, Cork, Ireland.

Chris Harrod next to Schöhsee, a lake in Northern Germany. The Max Planck Institute of Limnology, Plön, is located on its shores. Photo credit: Dr. Jonathan Grey, QMUL.

Chris Harrod talks with and answers a few questions about this month's Emerging Research Front paper in the field of Plant & Animal Science.

SW: Why do you think your paper is highly cited?

I think that our paper on the implications of climate change on fish has been well cited for several reasons. Although recognized for at least a quarter of a century, climate change is a large and growing issue in fish biology. This is because climate change has, and will continue to impact fishes at all levels of biological organization from the sub-cellular, the individual, the population through to the community/ecosystem-level and beyond.

This reflects the fact that that as thermal conformers, changes in water temperature affect almost every aspect of an individual fish's life, from the time spent developing as an egg, to the availability of food following hatching, through individual growth rate, consumption patterns and the diseases and natural enemies that a fish encounters through life. Furthermore, biologists, anglers, and commercial fishers are seeing shifts in the distribution of fishes that indicate large scale responses to changing climates.

All of these issues (and more) are important for those interested in the ecology, management, and exploitation of fishes. A final important factor that has definitely helped push the paper in terms of citations is the journal where it was published. The Journal of Fish Biology is a well-read and popular journal held in libraries in universities and research institutions across the World.

SW: What are the key developments that your review paper covers?

Conor Graham next to Schöhsee, a lake in Northern Germany. The Max Planck Institute of Limnology, Plön, is located on its shores. Photo credit Dr. Chris Harrod, QUB
Lead author Conor Graham next to Schöhsee, a lake in Northern Germany. The Max Planck Institute of Limnology, Plön, is located on its shores. Photo credit: Dr. Chris Harrod, QUB.

Our article asked a series of questions that, following many discussions, we knew were on the lips of many of our colleagues in fish biology (and associated fields). The review was designed to provide a synthesis and to represent the go-to reference of the effects of climatic variation on aquatic habitats in and around Britain and Ireland, and the likely ecological impacts of climate change on marine, brackish, and freshwater fishes. Fish biologists have long recognized the influence of climatic variables (e.g., temperature, precipitation) on fish ecology, and through the 2000s biologists were increasingly reporting shifts in geographical distribution of fishes around the UK.

Taking information from a range of scientific disciplines, including climatology, oceanography, limnology, physiology, fisheries science, animal behavior, genetics, and ecology, our review provides a detailed outline of the key issues and the likely responses of a range of ecologically and economically important fishes to predicted climatic changes. Although the review is focused on Britain and Ireland, the issues, habitats, and species described extend well beyond this geographical area, widening interest in the review.

SW: Would you summarize the significance of your paper in layman's terms?

We provided a detailed examination of how climatic variation affects fish and their habitats. We then used the best available estimates of future UK/Irish climate to make future predictions of the response of several important fishes that live in or around Britain and Ireland including herring, cod, perch, roach, and Atlantic salmon.

SW: How did you become involved in this research, and how would you describe the particular challenges, setbacks, and successes that you've encountered along the way?

Both Conor Graham (my co-author) and I did our Ph.D. research on cold-adapted fishes, and have long been keen to understand the impacts of climate change on these and other fishes. The interest continued and the Council of the Fisheries Society of the British Isles (FSBI) asked me to write a Briefing Paper on the subject suitable for non-expert readers (e.g., policy makers and stakeholders). This was produced in conjunction with Conor and another colleague (Jennie Mallela) and the FSBI subsequently commissioned a more focused review paper for the society's journal, the Journal of Fish Biology, which Conor and I wrote during 2008.

As fish ecologists who were not previously involved in climate change research, we faced a considerable challenge. Although we had a good combined understanding of fish ecology, the first issue was to how to deal with the huge amount of relevant material "available" in the literature, much of which was not actually easily available. However, at the time of writing, I was working at the Max Plank Institute for Limnology in Plön, Germany (now MPI for Evolutionary Biology) and the combination of the excellent library facilities and the actions of Brigitte Lechner, librarian extraordinaire, greatly aided our work.

We did not really encounter setbacks, but were gradually worn down by that enemy of us all—time. Like all colleagues, we were writing whilst juggling other commitments—in my case running my stable isotope ecology laboratory, and in Conor's case, maintaining his doctoral studies on salmon-trout interactions back in Ireland.

"In my opinion, politicians need to be prepared for some awkward questions if they fail to act on their responsibilities regarding climate change. Hopefully our review adds to the ammunition!."

We both feel that the paper represents a real achievement: colleagues and students continue to use it a resource, and I, as corresponding author, receive several emails a week asking for PDF reprints. The FSBI went on to sponsor an international conference on Fish and Climate Change organized by myself and Prof. David Sims (Marine Biological Association of the UK) in July 2010. This was a great success, bringing fish biologists of all backgrounds to Belfast to discuss the very issues discussed in the paper. It was particularly pleasing to me that many delegates at the meeting took the time to speak to me about the review and to pass on kind comments.

SW: Where do you see your research leading in the future?

In Belfast, my group works on a wide range of subjects including trophic ecology, rapid evolution, invasive species, and conservation ecology, and climate change is routinely considered in all these areas. For instance, temperature treatments are included in experimental studies wherever possible to increase our understanding of how fish (and other aquatic taxa) will respond to future climatic change. One area of great interest is how local adaptation may break down following climate change.

I'm currently on a three-year secondment at the Universidad de Antofagasta in Northern Chile, working on a project examining how upwelling zones provide trophic subsidies to inshore marine fish communities. Here on the edge of the Atacama Desert, climatic fluctuations are at the forefront of many peoples' thinking, including the fishers and biologists who have long recognized the influence of climate on fisheries productivity due to the El Nino-Southern Oscillation. The models we develop here will hopefully help us understand how global climate change will affect ecosystem function.

My work in Chile also includes collaborative studies with colleagues from Chile working on endemic fishes (Orestias Spp.) inhabiting high-altitude lakes, salares, and wetlands. Work by Chilean and French colleagues amongst others has led to these fishes being accepted as an increasingly valuable model for rapid speciation. Due to their distribution, these fishes already encounter extreme conditions (e.g., high UV, marked diurnal temperature fluctuations).

However, they will face even more challenging conditions following future climate change, especially considering the ongoing and increasing demands for water to support copper mining. I hope that future work will develop the means to allow the long-term conservation of these and other fishes.

SW: Do you foresee any social or political implications for your research?

Our research adds to the growing mass of evidence that climate change has and will continue to drive ecological change. As humans, we rely on fish for a series of ecological goods and services (e.g., for food, employment, recreation, indicators of environmental health). As such, any impacts of climate change on fish will have social and political impacts.

Young people are environmentally aware; they view how human activities impact the climate with a critical eye and are interested in how the future world will look and function. In my opinion, politicians need to be prepared for some awkward questions if they fail to act on their responsibilities regarding climate change. Hopefully our review adds to the ammunition!End

Chris Harrod
Lecturer in Fish and Aquatic Ecology
School of Biological Sciences
Queen's University
Belfast, UK
Visiting Professor
Universidad de Antofagasta, Chile
Antofagasta, Chile



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