EPA's Vessel General Permit and Small Vessel General

Anthropogenic threats
Although commercial harvests historically lead to black abalone depletion, current harvesting is
a small fraction of those levels. However, small removals are still significant in small
populations.
Although toxicology of abalone is poorly known, red abalone have demonstrated metabolic
breakdown when exposed to the pesticide 3-trifluoromethyl-4-nitrophenol (Viant et al. 2001).
Silver, cadmium, and mercury are also known to bioaccumulate in abalone, likely from ingested
algae (Huang et al. 2008). Update rates have been measured as 1.78 L g -1 d -1 for silver, 0.056 L
g -1 d -1 for cadmium and 0.32 L g -1 d -1 for mercury, of which 58 to 83%, 33 to 59%, and 65 to
78%, respectively, is assimilated. Abalone are known to bioaccumulate high levels of heavy
metals in the presence of high environmental concentrations (Wang et al. 2009).
Changes in sea surface temperatures have been suggested as a driving force in altering red
abalone distribution in the past (Braje et al. 2009); it is unknown what affect, if any climate
change may have on black abalone.
Critical habitat
On October 27, 2011, the NMFS designated critical habitat for black abalone This includes rocky
areas from mean high water to six meters water depth in the Farallon, Channel, and Año Nuevo
islands, as well as the California coastline from Del Mar Ecological Reserve south to
Government Point (excluding some stretches, such as in Monterey Bay and between Cayucos
and Montaña de Oros State Park) in northern and central California and between the Palos
Verdes and Torrance border south to Los Angeles Harbor. These areas include primary
constituent elements required by black abalone, such as rocky substrates to cling to, food
resources (bacterial and diatom films, crustose coralline algae, and a source of detrital
macroalgae), juvenile settlement habitat (rocky intertidal habitat containing crustose coralline
algae and crevices or cryptic biogenic structures (e.g., urchins, mussels, chiton holes,
conspecifics, anemones)), suitable water quality (temperature, salinity, pH, and other chemical
characteristics necessary for normal settlement, growth, behavior, and viability of black
abalone), and suitable nearshore circulation patterns (where sperm, eggs, and larvae are retained
in the nearshore environment).
Johnson’s seagrass
Description of the species
Johnson’s seagrass has only relatively recently been identified as a distinct species and therefore
no historical distribution information is available (Eiseman and McMillan 1980).
Distribution
Current distribution includes lagoons along approximately 125 miles of southeastern Florida
between Sebastian Inlet and north Biscayne Bay which means that Johnson’s seagrass has the
most limited geographic distribution of any seagrass in the world (Kenworthy 1997). However,
northern range extentions (likely temporary) have recently been observed (Virnstein and Hall
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