204 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



occurred subsequently. The results of the most 

 recent and intensive surveys are not generally 

 available, although two minor papers from one of 

 them have appeared (Norris 1953; Puffer and 

 Emerson 1953). 



Most of the study of coral reefs has been 

 faunistic or geological; some minor contributions 

 to the ecology of Gulf of Mexico coral reefs are to 

 be found in the publications of the Tortugas 

 Laboratory. The sponge grounds have been even 

 less adequately studied from the ecological stand- 

 point, although investigations are now in progress. 



Gunter's work in Louisiana and Texas 



Important marine ecological work, chiefly with 

 motile invertebrates and bottom-feeding fishes, 

 has been done by Gunter in the past 20 years on 

 the coast of Louisiana and Texas. The general 

 results can be divided into the following main 

 categories : 



1. A description of the relative abundance and 

 species mass of the larger motile vertebrates and 

 invertebrates. 



2. Description of seasonal cycles and move- 

 ments from Gulf to estuarine waters and return, 

 and seasonal variations in abundance, correlated 

 with temperature change. 



3. Distributions of organisms as related to 

 salinity. 



This work probably gives as complete a view of 

 the motile and free-swimming fauna of the bays 

 and shallow Gulf as there is for any coast of this 

 continent. While it describes the motile part of 

 the bottom community it does not add to knowl- 

 edge of the in-fauna of the bottoms. Life history 

 notes on the various important fish and Crustacea 

 with some data on food consumption were gathered 

 as a side issue. 



The work in Louisiana was carried on for 2 

 years from 1931 to 1933. It consisted of the 

 analysis of populations of bottom fishes over a 

 salinity gradient from almost fresh water in the 

 upper part of Barataria Bay to 3 miles offshore in 

 the open Gulf of Mexico. It was during this ini- 

 tial work that Gunter became interested in rela- 

 tive numbers of species mass which he emphasized 

 in later papers. In view of the impossibility of ob- 

 taining knowledge of total quantities of the species 

 involved, the relative numbers data of the animals 

 taken in J;he various environments seem to be 

 about as quantitative as can be obtained. This 



was used in estimating the relative species mass. 

 Any gear used gives a somewhat distorted view of 

 the actual populations, and the various ad- 

 vantages and disadvantages of the trawl were 

 considered. The results of this work were given 

 in Gunter (1936, 1938a, b). The seasonal varia- 

 tions in abundance of the whole fish population 

 and of various species alone are given. The 

 seasonal cycle of movement in and out of the 

 bays, giving somewhat regular arrivals and de- 

 partures of some species, was described. The 

 predominant family of fishes was found to be 

 Sciaenidae, followed by Otolithidae and Engrau- 

 lidae. Several abundant species of Sciaenidae 

 were led by the croaker, Micropogon undulatus. 

 Certain comparisons between the shallow water 

 fish fauna of the Louisiana and Texas coasts were 

 made later (Gunter 1945). This work was done 

 under the auspices of Slirimp Investigations of the 

 United States Bureau of Fisheries, and during 

 this time large catches of shrimp were made. 

 The data have not been published, but it can be 

 said that the motile fauna living close to the 

 bottom in the Louisiana bays and shallow Gulf 

 consists chiefly of the fishes described by Gunter, 

 the peneid shrimp, Penaeus setijerus and Penaeus 

 aztecus, and the blue crab, Callinectes sapidus. 



During the years 1941 to 1943 Gunter set up a 

 series of stations covering a transect from almost 

 pure fresh water (salinity 2.1 parts per thousand) 

 to 5 miles offshore in the Gulf of Mexico and 5 

 miles down the Gulf beach. This was on the 

 Texas coast and ran through Copano Bay and 

 Aransas Baj^ and out into the Gulf, a distance of 

 40 nautical miles. Thirty-two stations were 

 covered by trawl hauls, trammel nets, beach seines, 

 and fine-mesh net hauls on the beach and shores. 

 The original plan was to carry the work on for 2 

 years, but it was carried out for a year and a half, 

 and only 1 full year without spotty collections was 

 obtained. Even so, it covered bay and estuarine 

 waters and the connecting sea as extensively as 

 has been done in this country. 



Gunt€r (1945, 1950) was considerably impressed 

 with the fact that the bays serve as nursery 

 grounds for large numbers of organisms. For 

 instance, many fishes such as the croaker, Micro- 

 pogon undulatus, the redfish, Sciaenops ocellata, 

 the mullet, Mugil cephxilus, and several others 

 spawn in the Gulf and grow up in the bays. The 

 same holds true for the blue crab, Callinectes 



