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.


Videos - 2010

Grey Seal Hunt update Feb 09

Hay Island Seal Hunt Feb 08

Dying Ocean article on - Feb 14/08

Brief to MPs on seal hunt Nov 9/06

Evidence to NS govt committee
Oct 06

Seal Disease update Oct 06

"Inconvenient Truth" about sea life?

"Letter to Chuck Strahl

Seal oil leaves a fishy aftertaste

Seal Hunt defies Science, ecologically irresponsible 

DFO Seal Forum 2005

Ecosystem Science omitted from seal hunt plan

Seaweed Update 2005: rapid loss of Irish moss

Trust the Seals, Fear the Microbes... March 14/05

Something is Rotten in the Gulf: a new reason to stop the harp seal hunt Feb 11/05

Strangelove Ocean, CO2 revisited Oct 13/04

White Rocks, a subtle omen Oct 6/04

Fixing the basic model? Sept 22/04

Should Canada save the 'FAT CAT?' Wolffish preservation vs fishing Aug 28/04

Hungry humpback whales? Should we now scale back herring fisheries? Aug 25, 2004

DFO proposes new theory, exonerates seals in cod crisis July 25, 2004

Success? a positive meeting with Geoff Regan May 10, 2004

Minister Regan replies Apr 19/04

Grey Seal Conservation Society Apr 04                    

Ocean Health letter to DFO boss, Geoff Regan Mar 9/04

Fishermen, DFO, propose extermination of Grey Seals  Mar 2/04

HUGE error in DFO's baitfish count! Nov 16/03

Where have the fish gone? Sept 26/03

Plankton research is more urgent than seal research! May 8/03

Advice to Senate on rebuilding the fish stocks Apr 14/03

Mystery cod deaths in Newfoundland - Apr 7/03
Updated Apr 11/03

Starved Irish moss now bleaches to WHITE Mar 22/03

Thinking 'outside the box' Feb 6/03

Seals and Cod Dec 5/02

Advice to the FRCC on Atlantic cod, Nov 20, 2002

Starving Cod

What's New

 Marine Nutrient cycle - overview

Nitrogen cycling - sources of 'new' N

Fish eggs role in nutrient cycling

Fishing, whaling and the carbon cycle

Disappearing barnacles

Changing seaweed

Atlantic mackerel

Fisheries Research priorities



Coral Bleaching

Striped Bass and Atlantic Salmon

Gray Whales

Fishing vs Overfishing

Inshore vs Offshore

Atlantic Canadian fish stocks


Nutrient Overload

Small Fish

FAQ's Points of Debate

'How to Rebuild the Fish Stocks' '98

How to Rebuild the Fish Stocks 2003





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.


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


'Useless' fish with jellied flesh faces extinction in Canada





Canadian Government disinterest in scientific information that might impede the goals of the fishing industry: recent examples

Seal Disease Update - October 23, 2006 Responses from government.

Letter to Minister responsible for seal product safety/CFIA - May 20, 2006

Seal Oil leaves a Fishy Aftertaste (...and seals may transmit brucellosis) - April 20, 2006 (no accountability for this food safety oversight?)

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

 2005: Stop the Canadian harp seal hunt! The slaughter of seals only starves fish, and the massive waste, tons of seal corpses left to rot, kills bottom life, including the endangered cod.





















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?'

Recent Additions

Brief to Canadian Senate Committee studying "the grey seal issue" March 2012

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"

Videos explaining the basis of my theory that depleting the sea of fish slowed ocean carbon uptake.

Nova Scotia Grey Seal Hunt Update 2009 - government and industry flip-flop February 10, 2009

(Aside: a note to lobster fishermen - March 12/08)

Nova Scotia seal hunt at Hay Island - a new low in Canadian wildlife conservation - February 2008

Dying Ocean interview/article published on - February 14, 2008

Brief to Parliamentary Committee on Fisheries and Oceans - November 9, 2006

Seal Disease Update - October 23, 2006

Sea Creatures Make a Healthy Ocean Planet, Air Included - July 13, 2006

Letter to Chuck Strahl, minister responsible for CFIA, the agency responsible for food safety - May 20, 2006 (answer included in seal disease update October 2006)

Seal Products may pose human health risks because Canada processes seals under standards meant for producing "seafood and fish" rather than following the meat hygiene rules. - April 20, 2006

Seal Hunt Ecologically Irresponsible - April 2, 2006

DFO Seal Forum 2005 - Comments on the new Canadian Seal Hunt Plan: specifically, how ecosystem objectives should be incorporated into this plan, and also, a letter to the Minister of Fisheries and Oceans asking him to elicit science advice on the wisdom of the current seal hunt from DFO's ecosystem scientists - November 21, 2005

Seaweed Update, early summer 2005 - an increasing loss of Irish moss - July 11, 2005

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

Something (else) is Rotten... (a hypocrisy related to the earlier article) - March 8, 2005

Something is Rotten in the Gulf of St. Lawrence: hypoxia now threatens an "environmental disaster," and hypoxia is intensified by the Canadian harp seal hunt... - February 11, 2005

"White rocks" - the latest in the vanishing seaweed chronicles - October 6, 2004

Fisheries models fail to grapple with reality - a meeting with DFO scientists to discuss my alternate "model" of marine production - September 22, 2004

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

DFO publishes a new explanation for the cod crisis, admits cod are starving, and exonerates seals - an update sent to the Minister of Fisheries and Oceans. July 25, 2004

A positive meeting with the Minister of Fisheries and Oceans which he promises to pry open the door at BIO. May 10, 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

Grey Seal Conservation Society (GSCS) formed in Nova Scotia, April/2004

Ocean Health, Ocean Science, falter together Mar. 9/04 A letter to the Minister of Fisheries and Oceans, requesting an open dialogue.

Proposed Grey Seal hunt in Nova Scotia = Ecocide Mar. 2/04

DFO calculates skyrocketing small pelagic population, while fish predators starve...?  Nov. 16/03

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.

$6 million for new seal research?...Only if a holistic assessment is made of the ecology of seals. "Seal exclusion" projects make no sense while marine science cannot explain what is happening to the plankton  Brief submitted to Commons, May 8, 2003

Advice to the Senate on how to rebuild the groundfish stocks: start by looking at ZOOplankton April 14, 2003

Update on Newfoundland cod kill April 11/03

Mysterious cod deaths in Newfoundland - is this due to freezing, starvation or suffocation?   April 7/03. Predictable consequences of a zooplankton decline are the increasing starvation of cod, their concentration in inshore locations, and their vulnerability to hypoxic bottom water that can result from an un-moderated 'natural' phytoplankton bloom.

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.

Advice on Atlantic cod to the FRCC - posted Nov 26/02

The Downturn in Atlantic Cod - Nov. 6/02

Seaweed photo galleries

Vertical Migration of Zooplankton - does this behavior pattern enhance new production?

Challenging Basic Assumptions Re: Marine Nitrogen Cycling




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