Growth of sea
creatures and algae has slowed,
which implies declining ocean carbon uptake. This seems to be an
unanticipated, indirect impact of fishing, which is an important new
insight.
Where
have the fish gone?
Observations
and theory overview, 2003
Dalhousie University, Nova Scotia, Canada
Starving Ocean - CBC
show with Debbie MacKenzie and Farley Mowat. 2004
Farley Mowat's 1984
work, Sea of Slaughter, shows
the immense strength of the fish-powered carbon sink,
before it was damaged by fishing and whaling.
Fish lift nutrients to the surface water, fertilizing algae and powering
a natural carbon sink. But our
massive removal of fish, sea birds and marine mammals over centuries has
sabotaged this
carbon sink, like deforesting the land. If sea animals made a comeback, the
fish-powered carbon sink would
mitigate atmospheric carbon dioxide.
But this
idea - that fish boost ocean carbon uptake, and that science has
overlooked it - challenges accepted ideas and threatens the fishing
industry.
2011 - Scientists now report the carbon sink 'value' of living, moving whales, plus the carbon
'cost' of whaling, and suggest financial 'carbon credits' could now be
earned by stopping fishing and whaling, supporting the theme of this
website:
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
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. Nov 9/06:
Brief to MPs)
Atlantic Canada provides what might be 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.
Begun in 1999, 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.
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.
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.
Seal Hunt
Ecologically Irresponsible - March 29, 2006 - DFO managers
cherry-pick own scientific information to use as "science advice" on
seal hunting. (ignored)
"The problems we have today will not be
solved by thinking the way we thought when we created them."
- Albert Einstein
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?'
Update on
seals and cod - November 2010 - dramatic DFO evidence of fish stock
rebuilding in the presence of record high grey seal density in Nova Scotia
contradicts popular hypothesis that seals are "preventing cod recovery"
Trust the
Seals, Fear the Microbes... An appeal to DFO and Environment
Canada to abolish the harp seal hunt because it accelerates the general
degradation of the marine environment. - March 14, 2005
Saving the 'fat cat'
- two species of catfish, or wolffish, face extinction in Canadian waters.
DFO's pro-industry agenda clashes with the requirements of a new federal
law, the Species at Risk Act, and scientific objectivity is lost.- August
28, 2004
Hungry humpbacks?
Conflict between whales and herring fishermen in the Bay of Fundy, plus an
unexpected decline in the herring stock, may force a new conservation
strategy - August 25, 2004
'Pseudo-eutrophication?' - technical arguments regarding unexpected
inherent difficulties in distinguishing between a starving ocean and an
overfed one...but seaweed tells the tale. April 8/04
Where have the fish gone?
A fresh look at the Ocean - slides and notes from an invited lecture
given at Dalhousie University, Sept. 19/03. My most recent attempt to sum up
the major thesis of this website.
What's that
white stuff in the seaweed? Mar. 22/03 Long term, gradually increasing
trend for Irish moss to lose color in summertime culminated in pure white
banks of seaweed in 2002. Also:
Shifting
baseline of color in Irish moss Mar. 22/03 Seaweed descriptions in the
older literature suggest that bleaching of Irish moss was much less common
in the nineteenth century than it is today.
Thinking "outside
the box" - Feb. 6/03 A letter to the Minister of Fisheries describing
why, besides striking an urgent task force to study the ongoing loss of cod,
DFO Science must consider the role of "biological forcing" in marine
production.
Seals and Cod
- Dec. 5/02 - Interactions with seals have unexpected positive effects on
the growth of cod.
