[4]
blooms and
food chain consequences in large ecosystems, in Food Chains,
Yields, Models, and Management of Large Marine Ecosystems, edited
by K. Sherman, L. M. Alexander, and B. D. Gold, pp. 275-307,
Westview Press, Boulder CO. l992.
Figure 1: A trophic routing and impact model showing possible
linkages between nuisance or harmful algal blooms and various
marine food web compartments. The arrows illustrate direct and
vectored routes through which toxins and anoxia can impact the
depicted trophic compartments, causing recruitment failure and/or
mortality. (From Smayda, [1992]).
Figure 2: Expansion of the problems caused by harmful phytoplankton
species in the U.S. over the last two decades. The maps show the
HAB outbreaks known before (top) and after (bottom) 1972. This is
not meant to be an exhaustive compilation of all events, but rather
an indication of major or recurrent HAB episodes. In addition to
the toxic impacts shown, harmful (but non-toxic) micro- and
macroalgal species have caused whale and other marine mammal or
animal mortalities, occasional anoxia, habitat destruction, and a
general decline in coastal aesthetics in many coastal areas during
the last 20 years. Legend: Open circles---neurotoxic shellfish
poisoning (NSP); Darkened circles---paralytic shellfish poisoning
(PSP); Open squares---recurrent fish kills; Darkened
squares---ciguatera fish poisoning (CFP); Open triangles---brown
tide; Darkened triangles---amnesic shellfish poisoning (ASP).
Figure 3: Antibody and oligonucleotide probe-labeled HAB cells,
visualized using fluorescence. A). Immunofluorescent image of
ASP-producing Pseudonitzschia pungens var. multiseries
labeled with polyclonal antisera developed by Bates et al.
[1993]. Note the bright fluorescent outline around the frustule of
the diatom, and the autofluorescence of chloroplasts inside the
cell; B). Immunofluorescent image of Alexandrium fundyense
(causes PSP) labeled with monoclonal antiserum produced by
Sako et al. [1993]; C). Fluorescence image of A. fundyense
labeled with oligonucleotide probe targeting ribosomal RNA or rRNA
( Anderson, unpublished data). Note that the rRNA label is
throughout the cytoplasm.
Figure 4: (A) NOAA Coastwatch sea surface temperature (SST) image
from April 26, 1991 at 0305 hrs local time during an early spring
runoff event. The warmer (darker) coastal current that plays a
dominant role in PSP dynamics within the region is seen originating
near the mouth of the Kennebec River (KR) and extending past Cape
Ann (CA) and into Massachusetts Bay near Boston (B). PSP toxicity
was detected only in southern Maine (sM) at this time. Low
concentrations of A. tamarense were detected within
the plume further to the south, but well offshore in Massachusetts Bay just
north of Cape Cod (CC). (B) Image from May 12, 1991 at 1447 hrs
local time, about two weeks after FIG. 4A. The narrow band of
colder water (white) along the coast north of Cape Ann signifies
nearshore upwelling which has moved the warmer plume (dark) and
A. tamarense cells offshore, resulting in decreasing toxicity
in southern Maine shellfish and no toxicity in Massachusetts during
this time. (From Keafer and Anderson, [1993]).
Table 1. U.S. Finfish, Shellfish and Wildlife Affected by Toxic or Harmful Microalgal Species (Adapted from Anderson et al., 1993)
Harmful Algal Species Geographic Area Affected Organisms *
Alexandrium spp. (PSP) Northern Atlantic Mussels, surfclams, and Pacific Coast softshell clams, sea of North America scallops, butterclams, oysters, ocean quahogs, gastropods, lobsters, crabs Herring, salmon, menhaden, sandlance, mackerel and possibly other fish species. Whales, sea lions, sea otters
, sea birds Squid, zooplankton, benthic invertebrates
Alexandrium monilata Gulf of Mexico Oysters, coquinas, mussels, gastropods, fish
Pseudonitzschia pungens Gulf of Maine; Mussels f.multiseries (ASP) Eastern Canada Puget Sound, WA
P. pseudo-delicatissima New Brunswick, Mussels (ASP) Canada
P. australis(ASP) California Anchovies, sea birds
Probably P. australis (ASP) Washington, Oregon Razorclams, Dungeness crabs
Unidentified (ASP) Massachusetts, Maine Bay scallops
Dinophysis spp. (DSP) Nova Scotia, MusselsGulf of St. Lawrence, Canada
Prorocentrum lima (DSP) Nova Scotia, Canada Mussels
Prorocentrum spp. Long Island Sound Northern quahogs, Bay scallops
Gyrodinium aureolum Northern New Mussels, softshell clamsEngland (Maine)
Aureococcus anophagefferens New York, Rhode Bay scallops, mussels Island, New Jersey Anchoa sp., cladocerans
Gymnodinium breve (NSP) Gulf of Mexico, Bay scallops, surfclams, South Atlantic Bight oysters, southern quahogs, coquinas Tunicates Many commercial/recreationalfish species Sea birds, sea turtles, manatees
, dolphins
Chaetoceros convolutus Pacific northwest Salmon aquaculture, C. concavicornis possibly other species
Heterosigma carterae Pacific northwest, Salmon aquaculture Narragansett Bay Zooplankton
Unnamed gonyaulacoid Mid-Atlantic region Striped bass, flounder, croaker, mullet, menhaden, sea trout, pinfish, blue crabs, scallops
Gambierdiscus toxicus South Florida, Grouper, snapper, Prorocentrum limaFlorida Keys, mackerel, jack, Puerto Rico, U.S. goat fish, barracuda, Virgin Islands parrot fish, tang, P concavum
Hawaii, Guam and others P hoffmannianum,
Gastropods Ostreopsis lenticularis
Causative algae implicated, not confirmed.