An eco-shitstorm is coming...everything rests upon whether or not we come to terms with the politics of earth and sky, evolution and transformation. Otherwise, in our lifetimes, we shall suffer......the fall of nature itself."    - Bob Hunter

HOW MUCH DAMAGE HAS HUMAN FISHING DONE TO THE OCEAN? We thought we could fish forever, because the sea was a limitless protein mine. But dawning now is a realization that we were wrong about that. But how naive were we? And what price will be paid? Ocean life is dying back in unexpected ways: although there are fewer fish and other sea animals, more of them are starving, while waves of 'sickness' spread as primitive microbes gain the upper hand. Symptoms include spreading 'dead zones,' harmful algae blooms and a diminished presence of sea animal life in general. Is fishing implicated in all of this? This website challenges accepted views of how the ocean works and suggests an new interpretation of today's trends: failing ocean fertility induced by fishing. (Also challenged is Canada's decision to ignore seal diseases.

Atlantic Canada reveals what is probably the clearest evidence anywhere of the ecosystem-effects of persistent human fishing. The early 1990's crash of the once great Canadian cod stock is held up as a global cautionary tale against fisheries mismanagement, against greedy human 'overfishing.' But less well known is that the story is not that simple, that, at the level of scientific detail, so much has gone severely and unexpectedly wrong in Atlantic Canada...that the most basic assumptions underlying the 'science of overfishing/sustainable fishing' must now be questioned.

Zooplankton were unexpectedly and inexplicably lost along with Canadian fish stocks. If, as seems likely, this is part of the ecosystem impact of fishing, then this finding has global significance.

This website chronicles my observations, the evolution of my ideas about what is happening to ocean life, and my attempts to draw attention to politically undesirable information about changes in the natural world.

Evidence: Starving Fish (& whales?)

North Atlantic cod stocks are today widely reported to be in "bad shape," usually meaning that there are not many fish left. However, individual codfish, such as this one, typical of those caught off eastern Nova Scotia in Sept. 2002, are also visibly in very "bad shape." The "shape" is that of starving fish. Hold mouse over the cod above (for a few seconds) to see the contrast with the body shape of a well fed cod. Experimental starvation of cod by Canadian scientists shows this:

Besides the flattened belly profile, the cod starving in the wild (top photo) shows an unusually downturned head and reddened mouth as it appears to struggle to survive by bottom feeding at a size when it would normally rely largely on prey fish in the water column. This physical sign that adult cod are now struggling to survive by bottom feeding contradicts several current lines of thinking about the reasons for poor growth in cod today (e.g. cooler water depresses appetite, fish are genetically slower growing, excess seal predation is killing them...). A simple shortage of their normal prey appears to be the most immediate problem facing Atlantic cod. And cod are not suffering from excessive seal predation. Check out the mysterious cod kill in Newfoundland, April 2003.

The focus on feeding habits also helps to explain why Atlantic haddock stocks (naturally more oriented toward bottom feeding) are faring somewhat better than cod stocks today. An inventory of Atlantic Canadian fish stocks reveals the widespread nature of this trend.

Evidence: a Transformed Ecosystem

As the size and abundance of commercially targeted fish species has plunged in recent decades, populations of smaller, unexploited organisms, the 'foundation' species of the marine ecosystem, have also experienced major downshifts. Oceanic zooplankton is in decline, and NASA/NOAA has recently reported an apparent global declining trend in marine phytoplankton production. Evidence suggesting lowered marine nutrient cycling can also be seen along clean oceanic shorelines.

Example: A clean, rocky intertidal zone in Atlantic Canada was heavily dominated by barnacles (filter feeding animals) in summer, 1948, reflecting relatively high marine productivity at that time. (Photo from Stephenson and Stephenson 1954 J. Ecol. 42:14-70 ) Move mouse over photo to see this site in summer, 2002. Now dominated by rockweed with relatively sparse barnacle cover, with individual barnacles very small, this shift away from dominance by filter feeders, and towards dominance by seaweeds, offers classic evidence of a decline in "nitrogen loading" rates. (Carpenter and Capone, Nitrogen in the Marine Environment (Acad. Press, NY, 1983)) This pattern of shifting dominance from filter feeders to seaweed is also widely evident today in the tropics where mass coral bleaching and infectious coral epidemics signal the failing health of those once dominant filter feeders.

Changes in Seaweeds

Increasing nutrient stress is visible in long established seaweed populations such as this Irish moss (a red algae) in Nova Scotia, which has bleached to white during summer, 2002. (Hold mouse over photo to see the color of healthy Irish moss.) A pattern of gradual change across many seaweed species, including the common brown rockweeds, is consistent with a gradual decline in nutrient availability. Exceptions to this pattern appear to occur only in localized coastal areas affected by high levels of nutrient runoff. Does confusion in the seaweed diagnosis result from 'pseudo-eutrophication?'

Arguments

Standard views of the workings of the marine ecosystem do not predict, or explain, many of today's worrisome trends in marine life - from the failure of NW Atlantic cod stocks to rebound under a 10 year fishing moratorium, to the global increase in 'harmful algae blooms.' Although multiple factors undoubtedly affect the ecosystem, an overall decline in nutrient cycling or total "productivity" has not generally been considered to be one of them. This is because marine productivity has been thought to be "physically forced." Recognition of the strength of "biological forcing" has been lacking in traditional views, and this is the basis of the arguments offered here, including the reasoning that total  productivity can be reduced by significant living biomass removal (fishing). It is speculated here that, besides ecological functions such as floating spawn, one important route of biological forcing that has been missed may be the possibility that vertically migrating zooplankton not only shuttle carbon down to deeper waters, but they may also shuttle 'new' nitrogen up to surface waters.

All articles copyright Debbie MacKenzie