SE Gulf Of California Research Articles

Stomatopods of the genus Squilla (Hoplocarida: Stomatopoda: Squillidae) collected off the coast of Sinaloa, SE Gulf of California, Mexico, during the CEEMEX C1-C2-C3 cruises

A series of stomatopod specimens belonging to the family Squillidae was obtained during sampling operations off the coast of Sinaloa (Mexico) in 1990, during three exploratory cruises. A total of 466 specimens were captured with commercial otter trawls used in the shrimp fishery, between 9 and 128 m depth. All specimens belonged to the genus Squilla and were collected in 34 of the 62 sampling stations. The same four species were collected during each cruise: Squilla hancocki (231 specimens), S. panamensis (114), S. mantoidea (97) and S. parva (24). All trawls considered, the sex ratio (M:F) was 1.34:1 for S. hancocki, 1.72:1 for S. mantoidea and 1.23:1 for S. panamensis. Adult and subadult sizes were well represented in the samples considering the known maximum size (total length) of each species. Of the 34 trawls with stomatopods, 15 (44%) contained only one species, 15 (44%) two species and 4 (12%) three species; no sample contained all four species. No geographic distribution pattern was detected in regard to the distribution of the sampling stations with the highest number of species.

Fecundity and reproductive period of Paradella dianae and Uromunna sp. (Peracarida, Isopoda) associated with prop roots of Rhizophora mangle in a tropical coastal lagoon, SE Gulf of California, Mexico

Specimens of the estuarine isopods, Uromunna sp. and Paradella dianae living among Rhizophora mangle prop roots in a SE Gulf of California coastal lagoon system were collected from 11 stations, from October 1997 to September 1998. Among the ovigerous females, there was a positive, significant relationship between clutch size and TL for both species. The average size at first sexual maturity was estimated to be 1.54 mm with an average fecundity of 11 eggs for Uromunna sp. In the case of P. dianae, the average size at first sexual maturity was estimated to be 4.81 mm with an average fecundity of 19 eggs. On the basis of proportion and frequency of appearance of ovigerous females, prop roots in Urias seem more suitable as a reproductive habitat for Uromunna sp. than for P. dianae. Des exemplaires de deux especes d'isopodes d'estuaires, Uromunna sp. et Paradella dianae, associees aux racines aeriennes de Rhizophora mangle dans une lagune cotiere localisee au SE du golfe de Californie, on ete recoltes dans 11 stations, entre octobre 1997 et septembre 1998. Une correlation significative et positive a ete obtenue entre la taille de la couvee et la longueur totale (TL) de la femelle dans le cas des deux especes. La taille moyenne estimee a la premiere maturite sexuelle est de 1,54 mm, correspondant a une fecondite moyenne de 11 oeufs chez Uromunna sp. Dans le cas de P. dianae, la taille moyenne estimee a la premiere maturite sexuelle est de 4,81 mm et la fecondite moyenne de 19 oeufs. Prenant en consideration la proportion et la frequence d'apparition des femelles ovigeres, les racines aeriennes du systeme Urias semblent plus favorables comme habitat reproductif pour Uromunna sp. que pour P. dianae.

Two new species of Synalpheus Bate, 1888 (Decapoda, Caridea, Alpheidae) from the SE Gulf of California, Mexico

[Two new species of Synalpheus Bate, 1888 are described for the Gulf of California, Mexico, in the eastern Pacific. Synalpheus wickstenae new species, and S. stylopleuron new species, belong to the paulsoni group as defined by Coutiere (1909) and are morphologically closest to S. sanjosei Coutiere, 1909, and S. superus Abele & Kim, 1989. These new species are distinguished by a series of characters mostly related with the shape and position of rostrum and occular teeth, the relative length and length/width ratio of the rostrum, the proportion between cephalic appendages, the presence/absence of a dorsal spine on the palm of the minor cheliped, the proportion of dactylus and propodus of the third pereiopods, and the shape of the first abdominal pleura in males. Deux nouvelles especes de Synalpheus Bate, 1888 sont decrites pour le golfe de Californie, Mexique, dans le Pacifique est. Synalpheus wickstenae nouvelle espece, et S. stylopleuron nouvelle espece, appartiennent au groupe paulsoni tel qu'il est defini par Coutiere (1909) et sont morphologiquement proches de S. sanjosei Coutiere, 1909, et de S. superus Abele & Kim, 1989. Elles s'en distinguent par une serie de caracteres qui concernent essentiellement la disposition du rostre et des dents oculaires, la longueur et la relation longueur/largeur du rostre, la proportion entre les appendices cephaliques, la presence/absence d'une epine dorsale sur la paume de la petite pince, la proportion du dactylus et du propodus des troisieme pereiopodes et la forme des pleura du premier segment abdominal du mâle., Two new species of Synalpheus Bate, 1888 are described for the Gulf of California, Mexico, in the eastern Pacific. Synalpheus wickstenae new species, and S. stylopleuron new species, belong to the paulsoni group as defined by Coutiere (1909) and are morphologically closest to S. sanjosei Coutiere, 1909, and S. superus Abele & Kim, 1989. These new species are distinguished by a series of characters mostly related with the shape and position of rostrum and occular teeth, the relative length and length/width ratio of the rostrum, the proportion between cephalic appendages, the presence/absence of a dorsal spine on the palm of the minor cheliped, the proportion of dactylus and propodus of the third pereiopods, and the shape of the first abdominal pleura in males. Deux nouvelles especes de Synalpheus Bate, 1888 sont decrites pour le golfe de Californie, Mexique, dans le Pacifique est. Synalpheus wickstenae nouvelle espece, et S. stylopleuron nouvelle espece, appartiennent au groupe paulsoni tel qu'il est defini par Coutiere (1909) et sont morphologiquement proches de S. sanjosei Coutiere, 1909, et de S. superus Abele & Kim, 1989. Elles s'en distinguent par une serie de caracteres qui concernent essentiellement la disposition du rostre et des dents oculaires, la longueur et la relation longueur/largeur du rostre, la proportion entre les appendices cephaliques, la presence/absence d'une epine dorsale sur la paume de la petite pince, la proportion du dactylus et du propodus des troisieme pereiopodes et la forme des pleura du premier segment abdominal du mâle.]

Distribution of mercury in adult penaeid shrimps from Altata-Ensenada del Pabellón lagoon (SE Gulf of California)

The Altata-Ensenada del Pabellón lagoon system is located in the central part of Sinaloa state, NW Mexico. The major sources of pollution are represented by the waste effluents from the intensive agriculture and the urban sewage from the cities of Culiacán (population of 750 000) and Navolato (population of 50 000). In this lagoon system diverse penaeid shrimps occur; the crystal shrimp Farfantepenaeus brevirostris, the brown shrimp F. californiensis, the blue shrimp Litopenaeus stylirostris, the white shrimp L. vannamei and the Pacific seabob Xiphopenaeus kroyeri. With the purpose of knowing distribution and relative concentrations of Hg in the main tissues of penaeid shrimps, levels of Hg in five species from Altata-Enesenada del Pabellón lagoon on the SE Gulf of California were determined. Analysis were carried out by reducing mercury compounds after acid digestion reduction with SnCl 2 and detection by cold vapour atomic absorption. In general, hepatopancreas was the tissue where Hg was mostly accumulated, followed by muscle and exoskeleton. The sequence of Hg concentrations in the five species studied here for every tissue was: hepatopancreas L. vannamei > F. californiensis > L. stylirostris > F. brevirostris > X. kroyeri; muscle L. stylirostris > F. brevirostris > L. vannamei > F. californiensis=X. kroyeri and exoskeleton F. brevirostris > F. californiensis > L. vannamei > L. stylirostris > X. kroyeri.

Trace metals in tissues of resident and migratory birds from a lagoon associated with an agricultural drainage basin (SE Gulf of California).

With the aim of knowing Cd, Cu, Fe, Mn, Pb, and Zn concentrations in selected tissues of birds from two places at Altata-Ensenada del Pabellón lagoon in the SE Gulf of California, 39 specimens of 14 species were analyzed. Migratory birds in this study showed the highest values of Cd, Cu, and Pb in liver; Fe and Mn, in viscera; and Zn, in feathers. Concerning the resident avifauna, the highest levels of Cd, Cu, and Fe were detected in the liver, Mn in viscera; and Pb and Zn, in feathers. Regarding Cu and Fe, higher concentrations were detected in migratory avifauna, while Mn and Zn were more accumulated in resident waterfowl. In the case of Cd and Pb, both elements showed a tendency to be more accumulated in resident seabirds. Statistical comparisons showed that in carnivorous and omnivorous birds the resident component was the group with higher levels in more comparisons where mainly Cu and Fe were involved. In the rest of the metals the differences in the concentrations in the distinct tissues of migratory versus resident species were not clearly evident in one group in particular. In a few cases, carnivorous birds had higher levels of Cd than herbivorous and omnivorous birds; for the rest of the metals there was not a clear trend of metal accumulation.

Heavy metals in sediments and lobster (Panulirus gracilis) from the discharge area of the submarine sewage outfall in Mazatlán Bay (SE Gulf of California).

Concentrations of selected heavy metals in lobster (Panulirus gracilis) tissues and sediments (bulk and bioavailable fractions) from an area influenced by sewage discharge in Mazatlán Bay were determined. Cd, Cu, Fe, Pb, and Zn in the sediments showed enrichment factors higher than one related to the discharge and were higher than the lower values of the sediment quality guidelines proposed by NOAA and CCME. In addition to the high levels, relatively high bioavailability in the sediments was estimated for Cd, Cu, Mn, Pb, and Zn, suggesting a possible adverse effect on the associated benthic organisms. A high concentration of Cr, Fe, Mn, and Ni was found in the exoskeleton of P. gracilis. The hemolymph, hepatopancreas, gills, and gonads concentrate Cu, Cd, and Zn to levels higher than the available concentration in the sediments (BCF > 1). However, most of the metals studied in the edible muscle tissue in P. gracilis ranged within the recommended limits for human consumption, except Pb, which was found to be above the acceptable level for shellfish and represents a health risk.

Geochemical evidences of the anthropogenic alteration of trace metal composition of the sediments of Chiricahueto marsh (SE Gulf of California)

Seven sediment cores (60–80 cm) were collected at Chiricahueto marsh, a salt marsh influenced by agrochemical, domestic and industrial effluents. The concentrations of Ag, Al, Cd, Co, Cu, Fe, Li, Mn, Pb, V and Zn were studied in the solid phase at each 1-cm section. The profiles of Ag, Cd, Cu, Mn, Ni, Pb and Zn showed a slight recent pollution in the site with enrichment and anthropogenic factors higher than unity; and correlation analysis indicated a direct association with organic carbon. Al, Co, Cr, Fe, Li, and V concentration profiles displayed a negative correlation with organic C and positive with mud content and no consistent enrichment at surface. Based on the principal component analysis and correlation analysis, two principal groups of metals were identified. The first group includes Al, Co, Cr, Fe and Li, that are derived predominantly from the weathering of parent materials in the local bedrock; and the second group include most of the metals, which were relatively enriched at surficial sediments, that are produced mainly by anthropogenic activities such as agriculture (Cd, Cu and Zn), sewage effluents (Ag, Cd, Cu, Ni, Pb and Zn) and in lesser extent atmospheric deposition (Cd and Pb).

Distribution of Cd, Cu, Fe, Mn, Pb and Zn in selected tissues of juvenile whales stranded in the SE Gulf of California (Mexico)

With the aim of knowing the concentration and distribution of essential and nonessential metals in selected tissues of whales, analysis of Cd, Cu, Fe, Mn, Pb and Zn were carried out in kidney, liver and muscle of the gray whale Eschrichtius robustus and the sperm whale Physeter catodon. Whales were found stranded in the southeast Gulf of California. Individuals were in a juvenile stage; mean length of whales was 9.3 m for E. robustus and 7 m for P. catodon. Sequence of metal concentrations was Fe>Zn>Cu>Mn>Cd>Pb in E. robustus, and Fe>Zn>Cu>Cd>Mn>Pb in P. catodon. In E. robustus, highest concentrations of Cu, Mn, Pb and Zn (17.2, 19.6, 0.9 and 388 μg g −1, respectively) were measured in liver, Cd (5.7 μg g −1) in kidney and Fe (1009 μg g −1) in muscle. In P. catodon, the highest levels of Cu, Fe and Pb (48.6, 5200 and 4.2 μg g −1, respectively) were found in liver, Cd and Zn (94 and 183 μg g −1) in kidney and Mn (8 μg g −1) in muscle. Metal concentrations reported here were not considered to contribute to the stranding of specimens.

Distribution and Normalization of Heavy Metal Concentrations in Mangrove and Lagoonal Sediments from Mazatlán Harbor (SE Gulf of California)

Concentrations of heavy metals, carbonates, organic carbon and granulometry were examined in sediments from 60 sites within Mazatlán Harbor and adjacent areas. Regional distribution had a strong (for Al, Fe, Li and Ni) and weak (for Cd, Co, Cr, Pb, V and Zn) seaward concentration gradient decreasing from the upper lagoon. The highest concentrations for most metals occurred in fine-grained sediments from Infiernillo Estuary, the upper lagoon and the industrial zone. In contrast, lower levels were usually found in the sandy sediments of the navigation channel, port entrance and an area associated with sewage outfall. Analysis of transects in mangrove and lagoonal sediments indicated that the amount of fine material and organic carbon increases towards the margins where mangrove sediments exist. While metal variations were not clearly observed in most of the metals examined; only Ni, V, Pb and Cu showed a slight tendency to increase towards the margins. Sometimes lagoonal sediments had redox and texture characteristics comparable to those from mangrove substrate, thus competing because of a similar capture capacity of metals. Metal data were normalized against Al and Li using a combination of normalization techniques (95% prediction intervals, regional anomalies and enrichment factor). It was found that Al and Li were good normalizers for most of the examined metals and they are important constituents of one or more of the major fine-grained heavy metal carrier(s) and adequately reflect the granulometric variability in the sediments of the study area.

Cd, Cu, Pb, and Zn in Lagoonal Sediments from Mazatlán Harbor (SE Gulf of California): Bioavailability and Geochemical Fractioning

Cd, Cu, Pb, and Zn in Lagoonal Sediments from Mazatlán Harbor (SE Gulf of California): Bioavailability and Geochemical Fractioning

Cd, Cu, Pb, and Zn in lagoonal sediments from Mazatlán Harbor (SE Gulf of California): bioavailability and geochemical fractioning.

Cd, Cu, Pb, and Zn in lagoonal sediments from Mazatlán Harbor (SE Gulf of California): bioavailability and geochemical fractioning.

Trophic Conditions and Stoichiometric Nutrient Balance in Subtropical Waters Influenced by Municipal Sewage Effluents in Mazatlán Bay (SE Gulf of California)

This work presents results of a study carried out between February 1995 and August 1996, on the trophic state of coastal waters influenced by a sewage outfall in Mazatlán Bay. Dissolved nutrients (ammonia, nitrate, nitrite, total inorganic nitrogen, reactive silicate and inorganic phosphate) and phytoplankton were used as parameters. The relative abundance by phytoplanktonic group changed in the different sites, in some sites (monthly sampled) bacillariophyte was the best-represented group with abundance ca. 70%. In additional sites around outfall and where red tides blooms occurred, this group was lower representation on the phytoplanktonic community. The application of two trophic indices based on nutrient concentrations corroborated along with the Shannon–Wiener diversity index indicates that Mazatlán Bay can be regarded as a predominantly eutrophic system. Additionally, the stoichiometric balance criterion in all selected sites confirmed that the mean ratio for the nutrients calculated does not reach the Redfield ratio Si:N:P of 16:16:1.

Abundance and diversity of macrofauna (fish and decapod crustaceans) in Penaeus vannamei culture ponds in western Mexico

Polyculture involving shrimp and fish has not been developed in western Mexico. Shrimp farming along the west coast of Mexico has been estimated to occupy a total of 8000 ha, producing about 0.90 tons ha −1 in 1993. Abundance and diversity of macrofauna (fish and decapod crustaceans) associated with culture (MAC) of Penaeus vannamei were determined twice in a year, in a shrimp farm located 25 km south of Mazatlan, Sinaloa, SE Gulf of California, Mexico. A total of 4978 specimens of MAC was obtained; 2355 in June 1993 and 2623 in January 1994, totalling about 115 kg of fresh weight (0.34 to 0.87% of shrimp harvest). Fish represented 98.3% and 98.0% of specimens and 90.2–93.5% of total fresh weight; the rest were swimming crabs ( Callinectes). The abundance of Pomadasys macracanthus, Lile stolifera, and Dormitator latifrons mexicanus was high and remarkably constant at both harvests. Maximum diversity was observed in winter (January 1994). Dominance by fresh weight reflects the importance of Pomadasys macracanthus in both cycles, and of Cynoscion xanthulus in the second. Largest fish were Gobiomorus maculatus (19.0 cm total length (TL)) and Elops affinis (36.5 cm TL). When comparing sizes, fish showed either a very clear ( P. macracanthus, M. altipinnis and G. cinereus), slight ( L. stolifera and D. latifrons mexicanus) or obscure ( C. xanthulus) displacement towards higher values in the second, longer cycle. Callinectes arcuatus, the only abundant decapod crustacean harvested, also showed a remarkable stability as far as population size, fresh weight and size distribution were concerned.