Fish Working Group Report

Chairman: Steve Kerr
Rapporteur: Jake Rice

The Fish Working group used a Draft Proposal for a study on Georges Bank as a starting point. The general objective of the proposal, as presented by Ed Cohen of NMFS, was to relate changes in cod and haddock larvae to temporal variability of vertical stratification on the Southern Flank of Georges Bank. Major components of the study proposal included:

The Working Group concurred all components of the study were appropriate, and the survey design was sound, to the extent it was presented. A number of suggestions were made to expand the scope and scale of the study, consistent with objectives of GLOBEC and CCC. Specific augmentations include:

The discussion of Cohen's proposal evolved into a more general discussion. From the wide-ranging comments several general suggestions emerged. These should outline general areas of priority research, and guide development of additional specific proposals in many contexts, including both GLOBEC and CCC.

It was acknowledged that to evaluate marine aspects of global change we require a much more in-depth picture of the physics of all banks, to establish a background for any other work. the physical studies should focus on several factors, including:

The Working Group concurred that it was important to consider the effect of global change on the total energy in the ecosystem (a concept discussed by Louis Legendre, among others, recently). Questions within this context would include:

No specific studies were proposed within this total energy framework, but the framework should be considered carefully in planning any global change studies in marine systems.

The Working Group suggested researchers consider any study of marine consequences of climate change in the context of another set of questions. One should ask if global change will produce:

The Working Group then had a long discussion of the gaps in understanding of the effects of global change on adult fish. Although discussions commonly settle quickly into studies of early life history and recruitment processes, adults may be affected in many ways, and most processes are poorly understood, poorly quantified, and poorly modeled. It was noted that work planned by OPEN will address many of these problems, but additional work is appropriate. Among the foci for future directed research are:

The Working Group acknowledged that there are many excellent data sets on fish populations; many extending for decades, some for centuries. These data sets are often collected for specific purpose, usually stock assessments, and are greatly underutilized for other purposes, including global change impacts. Major analysis projects should be initiated to make more use of these historic resources. Candidate projects include:

The Working Group concurred that bottom substrate was important to many (probably all) life history stages of fish, as it is to benthos. Substrate characteristics are also poorly known for most areas. Research is urgently needed for to quantify substrate attributes on meaningful spatial scales. Then studies are needed to establish and quantify the linkages of the substrate attributes to each life history stage of fish. This quantification is important in the global change context both as a covariate (so data can be interpreted in meaningful ways), and because substrate characteristics may be altered by global change processes (altered erosion, deposition and sedimentation regimes).

The Working Group also reviewed technological needs from the fish study perspective. Many deficiencies were noted in both hardware and software tools. Among the requirements are:



The Working Group concluded with a second wide-ranging overview discussion. Three other general points emerged, the first two with relevance to the entire GLOBEC/CCC community. We need much more efficient methods to mobilize the existing data in every discipline, and produce data products which will be useful to other disciplines, as well as the specialists in one field. We need much more efficient ways of getting experts from diverse disciplines to come together often, and to work together. Finally the group agreed it would be necessary, at some point, to quantify the predators on, and prey of, fish larvae, juveniles, and adults; and the population dynamics consequences of the predator-prey interactions. That is not going to be an easily tractable problem.

As the Working Group adjourned, it agreed to RECOMMEND to the GLOBEC Steering Committee that it develop many of the general observations in this report into specific recommendations for Working Groups or other fora to ensure experts come together to proceed further with the work outlined in this report.

homepage contents previous newsletter next newsletter