Bottom trawling in the North Sea . Image by Ifremer.
The 4 billion tonnes of marine organisms that global fisheries extracted from the ocean between 1960 and 2018 resulted in the depletion of over 560 million tonnes of essential nutrients vital to ecosystem health, new research has found.
Australian Parvancorina minchami life restoration at MUSE – Science Museum in Trento, Italy. Image by Matteo De Stefano, Wikimedia Commons.
The growth and lifespan of Parvancorina minchami, small anchor-shaped animals that lived on the seafloor about 550 million years ago, resemble that of current marine invertebrates like golden shrimp and Baltic clam.
New research by a team at the Russian Academy of Sciences, Harvard University and the Sea Around Us initiative at the University of British Columbia shows that P. minchami’s longevity was about four years, that they could reach close to 20 millimetres in length, and that their pace of growth was similar to that of small recent invertebrates.
Hoi An fish market in Vietnam. Image by Jean-Marie Hullot, Flickr.
A recent study by researchers at the Sea Around Us – Indian Ocean, based at the University of Western Australia, the Changing Ocean Research Unit at the University of British Columbia and the University of Miami, shows that even with strong climate mitigation efforts, maximum catch potential is expected to fall by 58–92 per cent in the Pacific Islands and 65–86 per cent in Southeast Asia by the mid to end of the 21st century. These losses will likely result in fisheries failing to meet key micronutrient requirements in these regions’ coastal populations.
Measuring Baltic herring. Photo by Aleksey Kusnetsov, Wikimedia Commons.
As climate change continues to warm and deoxygenate ocean water, the size of fish, aquatic molluscs and crustaceans is showing a concerning reduction pattern. This pattern manifests a life history in which the animals exposed to rising temperatures grow fast when they are young but mature at smaller sizes than before and their final body sizes are also smaller than they used to be.
Farming Atlantic Salmon in Tasmania. Photo by Arthur Chapman, Flickr.
The growing appetite for expensive farmed salmon can leave coastal communities struggling to access affordable local fish like sardines and anchovies, new research published in Science Advances shows.
The paper, co-authored by researchers with Oceana and the Sea Around Us initiative at the University of British Columbia’s Institute for the Oceans and Fisheries, exposes the global aquaculture sector’s growing dependence on wild, small pelagic fishes which are frequently caught, processed, and ‘reduced’ to fishmeal and fish oil. Almost the entirety of the production of fishmeal and fish oil, that is, 87 per cent and 74 per cent respectively, is used to feed farmed fish.