Fishing about and about fishing

 

During the 2 decades, between 45 and 25 years ago, FAO Fisheries Resources Division, headed by Drs. Sydney Holt and John Gulland, was engrossed in introducing, teaching, and promoting population dynamics models as the main tool for stock assessment.   

 

Major management flops on one hand, and growing criticism on the part of fishermen and scientists not bewitched by the easily computerized equations, on the other, have forced fisheries and scientific establishments to start revising this methodology.  Uneasy noises have been coming also from the U.S. Academy of Sciences, the U.K. Royal Society, the ICES, and the Scottish Royal Society.  

 

FAO too started dismounting the already petrified paradigm by publishing reports that deal with statistical flaws in that methodology, and with correlations of massive fish stock fluctuations with climatic shifts and cycles.  

 

One, written by Prof. Klashtorin, I mentioned on this page in the October 2003 issue.  A few months ago and not a day too soon, FAO published  the FAO Fisheries Technical Paper (452), entitled:  Future climate change and regional fisheries: a collaborative analysis, (FAO Rome, 2003. 75 p), written by Dr. Gary D. Sharp.  It's a contribution to the growing understanding of the many enumerable factors that act on Earth in general, and the oceans in particular, and interact with each other within their respective ecosystems.  This knowledge is now evolving into a new scientific discipline: "Systems Ecology".  

 

Climatic shifts and incessant dynamics of oceanic systems have affected humanity also through their effect on fisheries – writes Dr. Sharp.  Repeated glaciation/deglaciation periods of millennia and decadal to century-scale climate changes were pushing back and forth animal and human populations more often than most people recognize.

 

The last two centuries, or so, were relatively mild.  They followed the  "little ice age", which not only annihilated the Greenland's Vikings and irrigated the fields of the Inca Empire, but by causing the collapse of the Baltic herring fishery, also influenced the whole Hanseatic commercial system. 

 

Unfortunately, our ability of forecasting of future climate changes is limited, because we have few really long time series that cover more than one or two complete fishery rise-and-fall cycles.  Our observation systems are so young, our time series so short, and our measurements so local that many (including satellite-taken) data have only been available since the 1950s, at best.  Misused to describe long-term trends, all they can reflect are just short-term convulsions and distortions on the back of the former.  As growing numbers of studies show,  oceans undergo parallel shifts, with dramatic changes in species abundance, composition, and distribution, and consequently also in fish stocks.

 

There're sufficient scientific examples and documentation to show that fisheries dynamics involves much more than only fish and fishing.  Oceans, hence fisheries, are affected by larger scale dynamic processes and forces. In fact, catches provide unique ecological climate indicators.  According to Dr. Sharp, the influence of the Earth-atmosphere-ocean-climate system on fish populations although well recognized, is still poorly accounted for in regional stock assessments. 

 

What Sharp is trying to do, is, in his own elegant style: "to refocus our objectives within our Solar-System and our own Earth’s Grand Fugue in which humans hold so many instruments, but…alas, not the Time-Keeper’s baton".  In short, with all the due respect to our sinful role in affecting the environment, we can only cause contortions, however nasty, upon major fluctuations that are caused by incomparably stronger global, solar, and cosmic forces.  The trend promoted by the Inter-governmental Panel on Climate Change is that our polluting is producing a major global change - a bit of megalomaniac message.  All the more that when scientists applied their favourite models to predict the global change to current climate they couldn't yield even approximately reliable picture of the present, so how could those models be used for forecasting?

 

The one thing that can be certain is that climate will continue to

change, and fish distributions and abundances will continue to respond as they have in the past. The fisheries most sensitive to climate change are also amongst the most affected by (non-fishing) human interventions such as dams, diminished access to up-or down-river migrations, filling in of wetlands, and other issues of human population growth and habitat manipulation and pollution, particularly expanded agricultural water use and urbanization.

 

Dr. Sharp is giving a wealth of scientific references in support of the need for the System-Ecology approach to understanding the dependence of fishery and their management on global climatic-oceanic forces.  His bibliography is 10 pages long.  But he leaves to the reader the identification of the "global warming buffs", and those "digital modelers" who who've been trying to assess stocks and run management schemes in separation from all the non-fishing factors that so overwhelmingly influence fisheries. 

 

Not that Sharp is disregarding the humans' role in modifying and damaging ecosystems by erasing habitats and depleting Earth's resources, fisheries included.  In the author's words:  "…ocean ecosystems begin on the highest mountains.  Waterways and all downstream and coastal water quality are very much at the heart of the dilemma.  High latitude dynamics and related ecological processes have been somewhat under-emphasized, since most humans are averse to such extreme environments.  If …our impacts in these regions become greater, it is clear that there will be dire consequences for those ecosystems…  … the species involved are truly specialized, and quite responsive to minor changes.  They and all (other) species need options even more than the most highly adaptable predators on Earth - humans do". 

 

On the other hand:  "It can be assumed that despite human activities, the solar system will continue to reflect the long harmonic interactions that have evolved over ages, long before life evolved… …long after the present amicable conditions have shifted from today’s supportive environments, toward ever more harsh ones – with inevitable consequences".  Sad outlook, but FAO and the author should be praised for bringing the global change and fisheries management into a long-neglected perspective.