Nuisance Algae and Harmful Algal Blooms of Buzzards
Filamentous algaeIn our region there are several genera of similar looking filamentous uniserate (strand of single cells) marine algae. These include species of the green alga Cladophora and Ulothrix, and several species of brown algae, most notably Pilayella and Ectocarpus.
The specimen in the panel to the right was delivered to us in April 2008 from Westport. This fine slimy feeling brown filamentous algae was purportedly densely covering floats and pilings in Westport Harbor. Although the specimen lacked reproductive structures, which would have helped in its positive identification, based on color, cell form, size, and branching, we identified it as Pilayella littoralis. Early spring 2008 was wetter than normal which would have added more nitrogen to Wareham's waters from land sources. This species is known to thrive under eutrophic conditions. Pilayella is also referred to as "mung" by some locals, and you may find this Cape Cod newspaper article of interest: Cape Cod newspaper article.
The filamentous brown algae Pilayella littoralis. Photo credit: Dr. Joe Costa.
Drift AlgaeDrift algae is a generic term for unattached algae that can accumulate and grown on the bottom of protected embayments. Cladophora is one of the more common species, especially in eutrophic embayments where it has the appearance of balls of green steel wool.
A fragment of Codium floating on the water.
Codium is a robust alga with a sponge-like texture, often growing in two-foot across bush-like shapes. While this alga can crowd out and shade other plants and algae, one of the most serious problems with Codium is that it is a killer of shellfish. It does this by the simple act of growing on shells, and causing them to be smothered (in the case of oysters it is nicknamed the oyster thief), or causing the shellfish to be pulled up from the bottom and washed ashore. In Buzzards Bay, this is a common occurrence for whelks, slipper shells (Crepidula), and bay scallops. The accumulation of dead shellfish in Codium wrack is one of the main reasons why this beach wrack smells stronger, and attracts more flies, than the native eelgrass beach wrack.
Read our article on a Codium population explosion off Wareham.