Tuna, Cod, Salmon, Mackerel, Anchovies ocean fish decimated
A new paper in the Journal PNAS confirms ocean plankton pasture collapse as primary cause of fisheries collapse (not overfishing).
Don’t click away in despair this story has a good news ending.
Published today in PNAS, “Reconciling fisheries catch and ocean productivity“ researchers built a mathematical model based on years of fisheries and plankton data to explore the processes that governs the transfer of biomass from the base of the food web to fish. The authors found that there are large regional differences in fish catch depending on the condition of the ocean plankton pastures those regions sustain.
Phytoplankton, the grass of ocean pastures, are the foundation of ocean life, providing the stuff/biomass/energy that supports virtually all marine species. These findings allow for better models for making catch predictions in different ocean ecosystems and how powerful impacts that result in collapse of ocean primary productivity are and will be affecting fisheries.
Phytoplankton grow in the light of day at the surface of the ocean using nutrients that are found in varying abundances depending on location. Generally near shore nutrients are abundant but just a short distance offshore certain vital nutrients, like iron, become very rare. Warming of the surface ocean due to collapse of plankton cooling, aka climate change as is the mistaken generic moniker given all global change, is increasing ocean stratification – the segregation of deep and surface waters.
The reports makes it clear that the modelled effects of ocean change and warming will be amplified in low and mid-latitude areas, where the models show that even modest to moderate declines in phytoplankton production, of up to 15%, could result in fish catch decreases that may exceed 50%.
Note this means that at present ocean phytoplankton collapse seen in the past 50 years already ranges between 20-50% over most of the world’s ocean pastures. This readily translates into an explanation of loss in fisheries catches due to ocean pasture collapse that is in close agreement with recorded declines in this period, true even if one excludes the touted “overfishing effects.”(Note this is an obvious interpretation of the results presented in the paper the authors dared not to state.)
Do The Math
(keep in mind as you do that Blue Fin Tuna are down to under 3% of their healthy population)
|Plankton Loss||Fish loss|
|1st 15%||50% remain|
|2nd 15%||25% remain|
|3rd 15%||12.5% remain|
|4th 15%||6.25% remain|
|5th 15%||3% remain|
“Using measurements of phytoplankton growth at the base of the food web to estimate the potential fish catch for different parts of the ocean has long been a dream of oceanographers,” says author Ryan Rykaczewski, Asst. Professor at University of South Carolina. “We know that these two quantities must be related, but there are several steps in the food chain that complicate the conversion of phytoplankton growth to fish growth.”
“Changes at the base of the food web among plankton are amplified when examining top and intermediate predators, such as fish,” says author Rebecca Asch, Asst. Professor at East Carolina University. “This indicates that climate change will have a substantially larger impact on species further up the food chain. This is important since these are also the species that we as humans depend upon as sources of protein to feed the world.”
This new work allows for more confidence in advising fisheries managers and policy markers on the impacts of climate change on fisheries production. The authors note that there is a need for ecosystem-based fisheries management strategies that consider potentially large regional changes in catch potential and a need for improved constraints on such changes.
We Can Bring Back The Fish
Moreover the work offers clear evidence supporting the practical solution to the global fisheries crisis which is to restore ocean plankton pastures to historic condition of health and abundance. The means to do this has been the subject of 30 years of global ocean science research on ocean pasture restoration (OPR), aka ‘iron fertilization’ by its Malthusian opponents.
It has now been proven in large scale ocean plankton pasture restoration work performed in dying Gulf of Alaska fish pastures that those pastures can be immediately brought back to historic condition of health and abundance.
In 2012 after many years of development work I completed a commercial-scale pilot project designed to restore and replenish a vital ocean salmon pasture in the N.E. Pacific. I provided the technology, methodology, and scientific and engineering expertise via a limited technology license and other guiding business agreements with the Haida Salmon Restoration Corporation. As the name of the business clearly stated the intent was to bring back the fish. And indeed we did.
The SE Alaska Pink catch in the fall of 2013 was a stunning 226.3 million fish.
This catch took place when the official projections were set at what was to be a “high number of 50 million fish” in the expected catch. Those extra 175 million ocean pasture fed fish came back because their ocean plankton pasture was enjoying the richest plankton blooms ever, thanks to my 11 shipmates and our work in the summer of 2012.
What the future holds for ocean fish almost everywhere is the restoration of their ocean plankton pastures to historic condition of health and abundance. Join me, lend a hand, help bring back the fish.