EFFECTS OF SPACE SHUTTLE EXHAUST PLUMES ON GILLS OF SOMEABSTRACT The first few launches of the space shuttle resulted in fish kills in a lagoon near the launch site. To study this phenomenon further, sheepshead minnow (Cyprinodon variegatus), sailfin molly (Poecilia latipinna), and mosquitofish (Gambusia affinis) were exposed to the exhausl plume in buckets placed near the launch site. An open bucket provided a full exposure, a partly closed one provided an intermediate exposure, and a closed one was the control. Three h after launch, the pH of the water from the full exposure had decreased from about 7 to about 3, Al and Fe levels had increased, and some fish had died. Gills of most fishes from full exposures and some from intermediate exposures were damaged. Gills, however, exhibited no aneurysms, mucus coagulation, or hemorrhaging. Some secondary lamellae swelled, some fused with adjacent lamellae, and others clubbed or retracted into the filament. Many lamellar pavement cells died and sloughed off. Mucous cells of intermediate exposure specimens bulged on the filament surface and pavement cells lost their microridges. Mineral deposits, probably aluminum oxide, occurred on gills of fishes from full exposures. Focally, pavement cells were eroded exposing the underlying structures. The sudden pH drop in the full exposures probably caused the gill damage. However, we could not determine the effect of previous exposure on the experimental fish, or whether gill damage was the lethal lesion. The possibility is indicated that some fish recover after exposure to the exhaust plume.

Four aerial survey projects were conducted between 1977 and 1986 to determine the abundance, density and distribution of West Indian manatees (Trichechus manatus), in the northern Banana River, Kennedy Space Center, Florida. Manatee density and distribution within selected portions of the 78.5 km2 study area were determined. Peak numbers of manatees occurred in spring of each year. The maximum counts increased from 56 in 1978 to 297 in 1986. Manatee abundance was lowest in the winter of each year. Mean density per flight increased from 0.52 manatees/km2 in 1977–78 to 2.73/km2 in 1984–86. This increase may reflect increases in the east coast population or shifts in the population distribution. Distributional changes were observed in the study area through time, with a lower percentage of manatees occurring in industrial areas and a correspondingly higher percentage of manatees in nonindustrial areas by 1985.

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SynopsisMonthly collections of clown goby, Microgobius gulosus, were made from March 1984 through February 1985 at two stations located at the head of the Banana River, Brevard County, Florida, as part of the long-term environmental monitoring program at the John F. Kennedy Space Center. A total of 18921 fishes comprising eight families and 12 genera was collected. M. gulosu(s represented 6.4% of the total catch. Populations of M. gulosus exhibited aggregation behavior, which varied in intensity depending on densities of individuals m-* and habitat characteristics. Capture data were best described by the negative binomial distribution. Mean estimates of individuals mm2 ranged from 0.0 to a high of 22.1 during periods of peak recruitment. The total length-weight regression for all individuals measured was log,, weight = -4.65 + 2.72 log,, length. M. gulosus obtained a size of 35-40 mm TL the first year and 50-60 mm TL the second year. Total lengths of all specimens ranged from 11 to 71 mm. Young of the year first appeared in May with smallest individuals collected in June and July. A protracted spawning period was observed. Stomach and gut analyses revealed that crustaceans and annelids combined represented 65% and 66% of the total diet for M. gulosus from stations 1 (open) and 2 (impounded), respectively. However, differences in proportions of the two groups were present between the two stations. Crustaceans represented 47.1% of the diet for gobies collected at station 1 and annelids 40.8% for specimens collected from station 2. Fecundity was low with the mean number of ova being 305 f 77.5 for females between 35 and 49 mm TL. Estimated mortality rate was approximately 95% annually.