As I mentioned in my first post, every year we observe something a little different out here in the Gulf of Alaska. For the past few weeks we have been catching more Young Of the Year (YOY) Walleye pollock than on any previous survey. Almost every time we haul the net back there are pollock, both at the surface and at depths up to 100 meters and deeper. At the same time there has been a relatively low abundance of juvenile rockfish and arrowtooth flounder and no signs of Pacific cod or sablefish.
Our local climate has also been different this year as we experienced a prolonged cold spring that kept the snow pack in the mountains and the ocean temps cool. Then in June, the state of Alaska had a mini-heat wave that melted snow and had locals peeling off clothing. The cold spring kept the streams and rivers cool and may have delayed the development of smolting salmon and would explain why we have caught very few pink and chum salmon on this survey despite the warm weather this month.
These temperature swings that we enjoy here on land are also taking place in the ocean and can influence reproduction timing and survival of marine fish. It is possible that the ocean conditions and prey availability this spring were optimal for juvenile pollock survival but not as beneficial for other species. Our physical and biological oceanography observations conducted on this survey will help us answer some of these unknowns as we investigate the mechanisms between climate variability and juvenile marine fish survival.