Double Whammy
As if the baffling bacteria, mycobacteriosis, that causes skin lesions and infections in upward of 70 percent of Bay rockfish weren’t bad enough, we’ve also learned the much-beleaguered Maryland oyster population is getting pounded as a result of the multi-year drought.
In fact, the annual oyster survey has Maryland biologists predicting this year’s oyster harvest will yield the smallest catch since 1870, the first year of record keeping. Biologists from the Department of Natural Resources say saltier Bay waters foster the two parasitic diseases, MSX and Dermo, that have been killing large numbers of oysters for decades.
Each situation in isolation is bad enough, but together they’re downright depressing.
The economic importance of rockfish to the regional economy is considerable, with the recreational fishery alone generating a quarter of a billion dollars a year for Maryland and Virginia, combined.
The rockfish situation requires further investigation, so the current study funded by the U.S. Geologic Survey’s National Fish Health Laboratory couldn’t have come at a better time. The hope is that Virginia and Maryland scientists will more effectively share research methodology and better coordinate findings to increase their understanding of the disease.
The oyster fishery is valuable, too, but these days more so for its ability to filter pollutants and help improve water clarity. If enough oysters were filtering, their work would spawn an ecological domino effect that could increase water clarity and benefit underwater grasses and other marine organisms.
The sad irony here is that the lack of rain actually helped underwater grasses bounce back by holding nitrogen and sediments in the soil, preventing algae blooms and turbidity that choke grass beds. Recent aerial surveys and groundtruthings revealed an encouraging improvement, for sure, but not sustainable improvement since it does not reflect any real reduction in nitrogen, the Bay’s worst pollutant.
The drumbeats for quick introduction of the Asian oyster — which is believed to be more resistant to the parasites than native oysters — are getting louder. Watermen understandably want the foreign oyster sooner than later. Their livelihood is beginning to resemble the box oysters they pull up: empty shells ravage by disease.
Yet resource managers in both states heeded calls by the scientific and environmental community to let the independent review by the National Academy of Sciences run its course before deciding on introducing the Asian oyster. They made the tough but right call. Non-native oysters have no known natural enemies and their environmental impact is uncertain, if not potentially devastating. Rather than speculate on what if, the prudent though difficult thing to do is wait and let science be our guide before unleashing an unknown organism on an already devastated estuary. z
Fish Are Biting …
Maybe — but the wind is howling and the rain is coming down in buckets. Trollers, when they can get out, are catching the biggest rockfish. Many captains think the ocean-run rockfish are here, but they can’t leave the dock to find them on a consistent basis. The shallow-water bite is over, though lots of white perch are still out there. And what about sea trout? If you’ve got any theories as to why it’s been a strange fall for them, I’d love to hear them.
Good news is, we still have a few weeks in which to make up for lost time. Weather willing, that is.
