The Great Lakes have seen successive invasions by non-native species that alter the ecosystem, including quagga mussels that filter the water and remove nutrients. At least partly as a result of the invasive mussels, Lake Michigan is becoming less hospitable to Chinook salmon, according to a new study led by scientists with the U.S. Geological Survey and Michigan State University.
The scientists concluded that stocking could help sustain a population of Chinook salmon, but that the lake’s ecosystem is now more conducive to stocking lake trout and steelhead salmon. These two species can switch from eating alewife, which are in decline, to bottom-dwelling round goby, another newly established invasive prey fish that feeds on quagga mussels. Continue reading “Invasive species shift Great Lakes ecosystems”→
Warming ocean will drive many commercially important species to new habitats; detailed projections can help coastal communities adapt
Climate change isn’t just heating the surface of the Earth. It’s also warming deep ocean water, and along the coast of the northeastern U.S. bottom-water temperatures are expected to increase by 6.6 to 9 degrees Celsius by 2100.
That means that commercially important marine species will also continue to shift northward, which is important information for fishermen trying to make living in the region. Just how much and when they will move is the subject of new research published this week in the journal Progress in Oceanography.Continue reading “Global warming means major changes for U.S. fisheries”→
Study projects 55 percent increase in acidity in next 50 years
There’s no stopping ocean acidification without stopping CO2 emissions, and that’s bad news for many marine species, including Dungeness crabs, according to new new research published in the journal Global Change Biology.
Tiny shell-forming organisms like pteropods and copepods are vulnerable to acidification, but will likely experience only a slight overall decline because they are prolific enough to offset much of the impact, the study found. But those impacts will cascade through ocean ecosystems to affect larger animals like crabs, that will suffer as their food sources decline. Dungeness crab fisheries are valued at about $220 million annually, and may face a strong downturn over the next 50 years. Continue reading “Ocean acidification to hit key fisheries”→
New lab experiments suggest that increasing ocean acidification could take a big bite out of the economically important cod fishery in the North Atlantic. The research suggests that the buildup of CO2 in the ocean could double the mortality of newly-hatched cod larvae.
Members of the German research network BIOACID quantified the impacts, showing that recruitment could decrease to levels of one quarter to one twelfth of the recruitment of the last decades. Cod have already been under intense fishing pressure for decades, and the new study, published in the online journal PLOS ONE, identifies climate change as an emerging new threat. Continue reading “Ocean acidification seen as huge threat to Atlantic cod”→
New vulnerability assessment to help guide fisheries management
Rapidly warming ocean temperatures off the coast of the Northeastern U.S. are likely to have a big impact on nearly all fish and other marine life in the region. Scientists with the National Oceanic and Atmospheric Administration carefully surveyed 82 species in a recent study, trying to identify which are the most vulnerable to global warming.
“Our method identifies specific attributes that influence marine fish and invertebrate resilience to the effects of a warming ocean and characterizes risks posed to individual species,” said Jon Hare, a fisheries oceanographer at NOAA Fisheries’ Northeast Fisheries Science Center (NEFSC) and lead author of the study. “This work will help us better account for the effects of warming waters on our fishery species in stock assessments and when developing fishery management measures.” Continue reading “Global warming: Goodbye to sea scallops?”→
Modeling projects huge economic losses in fisheries
A fine-grained look at climate change impacts in Canada suggests that coastal First Nations people might be hit especially hard, with fisheries catch potentially declining by 50 percent in the next few decades. That represents losses between $6.7 and $12 million annually by 2050.