Warming ocean conditions may be killing off seabirds and affecting fish populations, and it’s unlikely to change without intervention. That’s part of what University of Alaska Fairbanks Professor Russ Hopcroft will talk about for his lecture at the upcoming Kodiak Area Marine Science Symposium.
Hopcroft and his project partners study the northern Gulf of Alaska. He says in 2013 they first observed unusual weather patterns that stopped the Gulf of Alaska from losing heat in the winter, and the warm conditions have continued since.
Hopcroft says it’s the impact on the phytoplankton which then leads to the death of bigger life forms.
“Reductions in the overall quantity and the productivity of the phytoplankton community then makes less energy available as we work up through the sol plankton and toward things that we take out of the ocean such as fish, the health of the marine mammals and the seabird communities as well, which are dependent on them.”
Hopcroft says their observers, many of them volunteers in the Coastal Observation and Seabird Survey Team, are most interested in studying birds. That’s where they’ve gotten a lot of their statistics. But warming waters are likely having an impact on fish populations too.
“We know it’s likely to be affecting the productivity of the fish. The fish are not censused as well. Certainly some of the NOAA surveys for Pollock that went on during these warm years suggested incredibly low juvenile pollock recruitment during the survey, and we think that’s probably related to the warm period.”
He says the pattern of warm ocean conditions – and its consequences – won’t change without intervention.
“We don’t know how normal these last couple of years is, but I think the general assumption is that as the trends continue of warming climate, the likelihood of us having strings of warm years is expected to increase, and that what we’re seeing over the last couple of years may actually represent what the Gulf may be looking like in another 20 or 30 years quite routinely.”
The warming in the Gulf of Alaska ties into the much bigger global warming issue. Hopcroft says there’s a strong relationship between carbon dioxide concentration and global temperatures, and we must reduce carbon emissions in order to moderate temperature gains.
Hopcroft will give his talk on Wednesday. It’ll begin a little before 10 a.m. at the Kodiak Harbor Convention Center.