Do we need a good day of rain?

[ILV2F5H]

Ive been suffering real bad from allergies and we need a good wash over. Some of these rivers are too clear, which really doesnt help fishing that much. A good day or two of rain would be nice. What do yall think?

[chimo]

Without a doubt, everything needs a good soaking. Looks like maybe this weekend

Chimo

[Capt C-Hawk]

We need the rain for sure, I just hope it isn't already too late. Thinking back to last year we had plenty, so much that Fletcher's wasn't safe for boating most of the spring. Along with that we one of the most successful striper spawns ever recorded. I'm no scientist, but there must be some message there. I know I'm not looking forward to this year's YOY index.

[ictalurus]

Along with that we one of the most successful striper spawns ever recorded. I'm no scientist, but there must be some message there. I know I'm not looking forward to this year's YOY index.

You hit the nail on the head, Bob. The spawning success of striped bass and other anadromous fish is strongly tied to freshwater flow in March, April, and May. One of my buddies who studied anadromous fish recruitment for his PhD thinks March is the most important of the three. Seeing how dry it was in March and thus far through April, I suspect it may already be too late, but we don't know everything and a good bit of rain in the rest of April and May might help salvage things.

[Redfish12]

Plus... think about how rough it was last spring and how many of those big fish got out of the bay alive. However, they probably were caught this fall/winter in the waters off NJ/MD/VA/NC.

I wish there was a slot limit like Red Drum.

[camelbird]

I think I'd like some rain... never thought I'd say that but yeah I could go for some h20... I drove home today looking at the "haze" from the pollen and the heat, uugh

[kanvery]

Bill- That's really interesting. Short of writing a whole dissertation can you explain why a successful spawn is so dependent on good spring rains and freshwater flow?

[Capt C-Hawk]

Not very scientific but, the current flow keeps silt off the little beauties, and Webster's tells the rest....

uh-nad-ruh-muhs]
(a.) (of fish) migrating from salt water to spawn in fresh water

[ictalurus]

Bill- That's really interesting. Short of writing a whole dissertation can you explain why a successful spawn is so dependent on good spring rains and freshwater flow?

Only one dissertation for me, thanks.

Productivity of phytoplankton and zooplankton in the Chesapeake and other estuaries are driven in large part by the spring freshet, which is the increased freshwater flow resulting from snowmelt and the wet springs we usually have around here. The freshwater brings with it nitrogen, phosphorus, and organic matter, which combined with rising temperatures and light levels, kick off the spring phytoplankton bloom. After a while, zooplankton begin to increase in abundance as they feed and take advantage of all the phytoplankton and organic matter (detritus) in the water. After they hatch and absorb all their yolk sac, larval fish begin feeding on zooplankton. The more zooplankton there are, the better the larvae survive and grow. Also, there's strong evidence that there is better spatial overlap between larval fish and their zooplankton prey during wet years, at least in the upper Bay. In dry years, there are fewer zooplankton, and the spatial overlap might not be as good, either, which leads to poor survival of anadromous fish larvae and a low index for that year.

One of the big unknowns with climate change is the effect on anadromous fish reproduction. As winters become less snowy and more rainy, the freshet is predicted to occur earlier in the spring, or maybe even in late winter, and it might be less pronounced. If that happens, the phytoplankton and zooplankton blooms could end before the larval fish hatch if the timing of the spawn doesn't change. There is some evidence that striped bass, at least, have been showing up on the spawning grounds earlier based on historical data. This year's shad run was the earliest as long as I've been paying attention (about 12 years).

Interestingly, while wet springs are good for anadromous fish reproduction, they're bad for the fish that spawn offshore and recruit to the Bay during the spring, such as menhaden, spot, and summer flounder. Those species do better during dry springs. I'm not sure of the mechanism there, but I think it has to do with the prevailing winds and currents at the mouth of the Bay.

Because of the strong influence environmental conditions have on larval fish survival, it's possible to have low reproductive success even when the stock size is high. Similarly, a banner index year can occur even when stock size is low, which is how striped bass recovered after the moratorium. I think it was the 1987 or 1988 year class that started off the striped bass recovery, which really revved up in the early to mid 1990s (especially 1993 and 1996), which was a wet period.

[ILV2F5H]

Marine Biology 101....good stuff

[kanvery]

That was awesome! Thanks! So going off of what you said Bill, is there a better chance of a few flounder at the baybridge this year? A friend of mine caught one while drifting in front of Sandy Point one year. That could be really cool if they were there in any sort of numbers.

[jffoley]

Marine Biology 101....good stuff

+1 Good stuff, Bill! I get some of that. I went to college to be a marine biologist but washed out. Hurt my brain. That or ADHD! Or maybe too much partying. Switched to computers and have been able to pay the rent/mortgage since the late 70's. Go figure...

Now, if we can figure out the environmental conditions that affect weakfish...

Very late 70's by the way. :-)

[ictalurus]

Glad I could help.

When I mentioned flounder, spot, etc surviving better and coming into the Bay in higher numbers, I meant the larvae and juveniles. Flounder and spot grow pretty fast, but the ones that are hatching now won't be keeper sized this year. If this year turns out to be a good year for coastal spawners, we'll have a lot of the little, finger-sized spot around during the summer like we did a few years ago. This year's flounder might be catchable by the end of the summer, but they'll be hand-sized. It would take a few years for them to get to be keeper size.

I don't know of any research that focuses on the abundance of older fish with regards to salinity in the Bay, but it may exist. It's a little more complicated for bigger fish because they can go where they please based on environmental conditions, food, etc. Larvae depend on the wind and currents for transport for the most part. The salinity in the Bay and tribs increases when it's dry, which allows fish that prefer higher salinity to move farther up the Bay. I think it was 2007 and 2008 that were really dry, and I caught a number of almost-legal redfish and flounder during the summer of those years. It was even drier in 2010 (I think I have the year right), and I was licking my chops in anticipation of clobbering some flounder and maybe even getting a slot red in Maryland. I didn't catch a single redfish that year, only heard of one or two that were caught, and even the flounder gurus at the Tackle Box couldn't find any flounder. I have no idea why that happened. It could've been that the reproductive success for flounder and reds might've been low 3 or 4 years prior to that. I also heard that there might've been a winter kill in North Carolina that year, but I couldn't find anything definitive. So I would guess (barring a wet summer) that it would be possible to get some flounder farther north this year than usual, but I wouldn't bet the farm on it.

[ronaultmtd]

Thank Goodness it is raining right now in Southern Maryland- my allergies are killing me-