Wisdom from Russia - now in English

Its title was translated to "Cyclic Climate Changes and Fish Productivity".

I wrote then: “The 2005 Russian book represents the most authoritative and-up-to-date analysis of the effect of climatic and planetary factors on fishery resources, in particular, and fishery ecosystems, in general. To make it accessible to the rest of the world, it should soonest be translated to English, for it would open the eyes of fishery scientists and managers to the bitter truth that they cannot 'recover' a stock, which is on the downward slope of its multi-annual variation. Neither should they depress fishing of a stock that's half way up on the upwards slope of its cycle. Hopefully, it will help in so much needed overhauling of the prevailing fisheries science-cum-management system”. The whole article can be read at www.worldfishing.net/magazine (go to Ben Yami) and at www.benyami.org (go to Ecology and click on “Enlightenment from Russia”).

Recently, VNIRO published the book's English version edited by Dr Gary D Sharp. It is available from Science-Export Russia, 90, Profsoyuznaya St., Moscow, 117997, fax: +7(495) 334-7140; +7(495)-334-7479; email: naukaexport@naukaran.ru.

So now every English reading fishery scientist and manager can read the Russian study. And they all should. This 223 page study deals with relationships between climate change and fish productivity in ocean ecosystems for the last 1,500 years, and unfolds the 50-70-year climate fluctuations as related to fish production dynamics of major commercial species populations. It is highly relevant to the old question: what influences the long-term fluctuations of major commercial stocks more, climate or fishing? The authors use what they call a 'simple stochastic model' to predict the likely trends of basic climatic indices and thus the state of some commercial fish populations for several decades ahead.

What goes up and what goes down

In the June issue World Fishing reported on drastic cod quota cuts in Iceland, with which many Icelandic fishermen and owners disagreed, insisting that there is much more cod in the sea than the assessment of the country's Marine Research Institute. “There's a lot of cod everywhere,” they said. Interestingly enough, the Russian study agrees with the Icelandic fishermen's observations; it says on the basis of an almost 100-year long time series that the commercial stock of Northeast Arctic cod (Gadus morphua), in which they include also the Icelandic stock, should be now on its way up, to climax between 2015-25. So let me point out some more of the study's findings and predictions, so that the readers can get an idea where certain important fisheries are going. One can see that different species react differently to climatic fluctuations and that some come up while the others are diminishing.

The catches of Pacific salmon (Orconhynhus spp) that have been sliding from the 1990s peak (I think that West Coast American salmon fishermen would agree) should bottom out at about 2015-20. Japanese sardine (Sardinops melanosticus), which peaked in the late 1980s and has been sliding since would bottom out about 2015. The California sardine (Sardinops careulae) had good years between 1980 and 2004 and should now be on its way down to start climbing around the 2030s while the 2020s would be bad. The Peruvian sardine (Sardinops sagas) and the European sardine (Sardina pilchardus), abundant in the 1980s through the mid 90s, would both be on their way down to ebb between 2010 and 2020. The Chilean jackmackerel (Trachurus murphyi) peaked between the mid 1980s and mid 90s and has been decreasing since - the trend will change only after 2020.

The total stock spawning biomass of Atlantic spring-spawning herring is still climbing from its 1965-85 low, but it's about to change the trend after 2010-15. The catches of Alaska pollock (Theragra chalcogramma) that have been sliding since the 1990s should change the trend within a few years. The South-African anchovy (Engraulis capensis) should soon climb out from a 10-year trough. The South-African sardine (Sardinops ocellatus) fluctuates almost conversely: it ebbed between 1980 and 2000 and should presently start climbing to climax at about 2020. Finally, the Japanese anchovy (Engraulis japonicus), now on it's upwards trend, would start to diminish in about five years time.

Not so simple

Things, of course, are not as simple as the projected general trends in fish populations, which are also subject to unpredictable, short-term changes, due to, mainly but not only, man-induced factors, fishing and otherwise. Klyashtorin and Lyubushin detrended the global temperatures time series using standard statistical techniques and obtained the about 60-year long cycles and clearly distinguished maxima in the 1870s, 1930s and the 1990s. Recently, scientists from the Leibniz Institute of Marine Sciences in Kiel, Germany, as well as others from NASA, predicted that notwithstanding or within the 'global warming', if indeed a major climate change is now occurring, we are entering at least a decade-long cooling period. This again fits Klyashtorin and Lyubushin's pattern, including their predicted consequent marine biota fluctuations.

Nonetheless, in general, we have got the long, long waves of major climatic changes, the last one being the 'little ice age' between the 15th and 19th centuries, on which the 50-70-year fluctuations are riding piggy-back, so well described by the authors, which in turn, are often distorted by short-term ups and downs. Commercial fish populations are expanding and shrinking accordingly, although not exactly concurrently, some preferring the cooler periods, others the warmer periods. It is high time that this is all taken into consideration, not only at the academic level, which apparently started paying attention to the dynamics of fisheries ecology, but also at the levels of fisheries management and its scientific advisors that still appear to run things and models, as if they could by quotas and moratoria do away with climate induced fish stocks variations.