Marine Resources Assessment for the Marianas Operating ... - SPREP

AUGUST 2005 FINAL REPORT
♦ Bryozoans (Moss Animals)
Status—Bryozoans are managed in Micronesia as part of PHCRT and have EFH designated within
the boundaries of the study area (WPRFMC 2001; NMFS 2004c). While bryozoans are probably very
diverse in the study area (e.g., Tilbrook 2001), only one species (Penetrantia clinoidales) is described
on Guam (Paulay 2003c). Bryozoans are economically important for bio-prospecting and as marine
fouling organisms that interfere with boat operations and clog industrial water intakes and conduits
(WPRFMC 2001).
Distribution—Bryozoans are inhabitants of tropical Pacific reefs ranging from Hawai’i to the Indian
Ocean (Colin and Arneson 1995).
Habitat Preferences—Though widespread on tropical reefs, bryozoans are often not recognized due
to the fact that they occur in mixed associations with algae, hydroids, sponges, and tunicates on older
portions of coral reefs (WPRFMC 2001). These benthic sessile organisms occur from the intertidal
zone to abyssal depths (WPRFMC 2001). Forming encrusting, erect branching or foliose colonies,
bryozoans attach to rocks, corals, shells, other animals, mangrove roots, and algae or grow on
shaded surfaces on the undersides of coral heads, rock ledges, rubble, and fill cavities within the reef
structure (Sorokin 1995). Encrusting forms are found everywhere, whereas the erect and delicate
branching or foliose forms are typical of more protected areas (Sorokin 1995; WPRFMC 2001; Paulay
personal communication).
Life History—Bryozoans are colonial animals that develop from a sexually-produced zooid (Hawaii
Biological Survey 2001b). The asexual budding of the primary zooid develops a group of daughter
cells which will undergo a succession of budding and production of daughter cells (i.e., bryozoans are
colonies of zooids). Most marine bryozoans are hermaphroditic (produce both eggs and sperm).
Bryozoans release sperm into the water column and retain fertilized eggs in a cavity where they are
brooded before larvae are released into the water column (WPRFMC 2001). Bryozoans exhibit a
positive phototropic reaction, but become negatively phototrophic before metamorphosis, settling in
dark places on the reef. This may be dependent upon day length and temperature (WPRFMC 2001).
Most bryozoans settle on hard substrates, some settle on sand (Hawaii Biological Survey 2001b).
♦ Crustaceans (Mantis Shrimps, Lobsters, Crabs, and Shrimps)
Status—Crustaceans of the orders Stomatopoda (mantis shrimp) and Decapoda (shrimps, lobsters,
and crabs) are managed in Micronesia as part of CMUS and PHCRT by the WPRFMC (1998, 2001).
Over 839 crustacean species (36 stomatopods and 672 decapods) have been reported from the
CNMI and Guam (WPRFMC 2001; Paulay et al. 2003a) and have EFH designated within the
boundaries of the study area (WPRFMC 2001; NMFS 2004c). Currently, no data are available to
determine if all crustaceans of the PHCRT are approaching an overfished situation; lobsters are
probably overfished (NMFS 2004a; Paulay personal communication). Stomatopods are of little
economic importance due to their limited use in subsistence fisheries and ornamental trade.
However, decapods are very important in commercial, recreational, and artisanal fisheries with limited
use in the ornamental trade (except shrimp) throughout the tropical Pacific (WPRFMC 2001). None of
the species found in the study area are listed on the IUCN Red List of threatened species (IUCN
2004).
Distribution—Crustaceans are amongst the most abundant and diverse marine organisms in waters
of the Pacific tropical and subtropical islands. Crustaceans are found in all tropical and temperate
seas of the world (Eldredge 1995).
Habitat Preferences—Reef crustaceans are one of the most diverse and abundant groups of the
coral reef vagile and sedentary benthos (Sorokin 1995). Crustaceans occur over a wide variety of
coral reef habitat and associated environs including cavities of coral and rock or smooth-walled
burrows on sandy bottoms (mantis shrimps), pockets of corals, among rubble, or buried in sand on
reef flats and in seagrass beds (penaeid, caridean, and stenopodid shrimps), subtidal holes or
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