Monday, April 16, 2012

Warm Weather Stimulates Bay Wildlife

Bay getting off to a warm start
"There's a couple of things that are clear right off the bat, one of them is for our blue crabs," says Lyn Fegley, with the Maryland Department of Natural Resources. "Last year we lost a lot of our big crabs in Maryland because of cold water temperatures. This year, that won't happen."

In addition to more crabs, Pat Gilbert, with the University of Maryland Center for Environmental Science, says so far algae are getting a head start, too.

"They're responding just like our spring plants on land," says Gilbert. "As temperatures warm, they start growing more rapidly."

It's unclear as to whether or not the growth in algae will mean a bigger dead zone--hypoxic or low-oxygen areas in the water--this summer because while it's been warmer, it's been drier, as well. That means fewer nutrients are washing into the Bay to feed algae.
We have super dense algae bloom up where I work in Edgewater.  The water looks like light chocolate milk, and the oxygen saturation at the surface is above 100% due to the high rate of photosynthesis, and staying there all night.  I looked at it under a scope a couple week ago (before it got really thick) and it was a dinoflagellate, probably the Prorocentrum minimum bloom that has been reported recently.
Something else swimmers and other Bay visitors may notice is a rise in the sea nettle or jellyfish population.

"If things remain warm and dry, as we come into [the] May, June time frame, we would predict an early appearance of sea nettles and for their distribution to shift northward," says Raleigh Hood at Horn Point Laboratory.
Yep, warm, dry springs bring out the worst in Sea Nettles.  They like the higher salinities in a low rain year.  Last year was a bad year for nettles, so we're probably due.  Typically, they're bad off our beach by about the beginning of July.  Last year they hardly appeared at all due to the low salt content of the water.
These affects may even occur as far north as Baltimore. Other scientists say rockfish could spawn early, and birdwatchers say many bird species are arriving weeks before their usual schedule.
Rockfish (Striped Bass for the non Chesapeake readers) start spawning when water temperatures on the spawning grounds (up near the Susquehanna flats, and up in the upper brackish area of many tributaries) when temperatures range from about 60-70 F.  On Friday night, the water temperature in the Bay here was 60, and the shallow waters of the tributaries warm up faster, so in all likelihood the rockfish are already spawning.  However, warm dry years are not traditionally good years for baby rockfish, so I anticipate a poor "Young of the Year" index this year.

Trying to "blame" the warm spring on global warming? Fuhgeddaboudit!

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