The biggest threat is to shellfish larvae and small seed – in spat-on-shell tanks and nursery systems. Survival could be impacted due to low dissolved oxygen (from the algal cell die off, which consumes available oxygen) or by the algal cells clogging screens in nursery systems and reducing water flow. The algae could also impair feeding by “clogging” shellfish gills and in some cases could have toxic effects.
There are a host of agencies working together to actively monitor the blooms – VIMS, DEQ, VDH. Bloom locations have been reported in the lower Chesapeake Bay, including the Lynnhaven, The Lafayette and the Elizabeth Rivers. As the summer and heat wear on, it is possible that the threat may remain in the area until cooler temperatures and higher winds arrive.
If you are a local oyster-gardener or know one, please remember to report oyster mortality to the Virginia Institute of Marine Science contact at firstname.lastname@example.org.
~ by Grace Moran
Special thanks to Florence ‘Flo’ Womacks for use of her photo.