Hernandez-Carmona G.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Riosmena-Rodriguez R.,Autonomous University of Baja California Sur |
Ponce-Diaz G.,Centro Interdisciplinario Of Ciencias Marinas Ipn
Journal of Applied Phycology | Year: 2011
An experimental study of the effect of artificial nutrient supply on understory algae was made during 1997 El Niño Southern Oscillation (ENSO) at the Mexican Pacific coast of Baja California. Twelve quadrats of 1 m2 were placed on the sea bed. Six quadrats were used as controls, and six were treatments with added artificial nutrients. Nutrients were supplied using polyvinyl chloride (PVC) pipes filled with slow-release inorganic fertilizer. The algae species composition and cover in each quadrat were estimated using the random point quadrat method. The percent of cover was tested using a multifactorial analysis of variance, and significant differences were obtained by post hoc Tukey's HSD test. The analysis was carried out annually, seasonally, and seasonal and monthly for each species. The seawater temperature was recorded, and compared with historical data. The bottom and surface seawater nitrate concentration were measured. Twenty-five species of macroalgae and one seagrass were identified. The most abundant species was Corallina vancouveriensis (-N=19.8% and +N=26.6% average cover). The other species had lower than 10% cover. Significant differences of species percent cover between experimental groups (+N and -N) were detected in the annual analysis (p=0.059). Seasonal analysis did not showed significant differences for any season. Monthly analysis showed significant differences in average percent cover when nutrients were added in eight species in different months: Bossiella orbigniana (August); Colpomenia sinuosa (June); Corallina officinalis (August); C. vancouveriensis (June); Dictyota flabellata (September); Eisenia arborea (June); Gracilaria marcialana (June); Macrocystis pyrifera (October), and the seagrass Phyllospadix torreyi (September and December). In conclusion, not all seaweed species are sensitive to nutrient addition during the ENSO years. In this research, we found eight species and one seagrass that had a positive reaction to the nutrients during the most severe stage (summer) of the ENSO. © 2011 Springer Science+Business Media B.V.
Rodhouse P.G.K.,British Antarctic Survey |
Pierce G.J.,University of Aberdeen |
Pierce G.J.,University of Aveiro |
Sauer W.,Rhodes University |
And 49 more authors.
Reviews in Fisheries Science and Aquaculture | Year: 2015
Some 290 species of squids comprise the order Teuthida that belongs to the molluscan Class Cephalopoda. Of these, about 30-40 squid species have substantial commercial importance around the world. Squid fisheries make a rather small contribution to world landings from capture fisheries relative to that of fish, but the proportion has increased steadily over the last decade, with some signs of recent leveling off. The present overview describes all substantial squid fisheries around the globe. The main ecological and biological features of exploited stocks, and key aspects of fisheries management are presented for each commercial species of squid worldwide. The history and fishing methods used in squid fisheries are also described. Special attention has been paid to interactions between squid fisheries and marine ecosystems including the effects of fishing gear, the role of squid in ecosystem change induced by overfishing on groundfish, and ecosystem-based fishery management. Copyright © Taylor & Francis Group, LLC.
Chavez E.A.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
de lourdes salgado-rogel M.A.,Instituto Nacional Of Pesca Inapesca |
Palleiro-Nayar J.,Instituto Nacional Of Pesca Inapesca
California Cooperative Oceanic Fisheries Investigations Reports | Year: 2011
The catch of the warty sea cucumber Parastichopus parvimensis of northwestern Baja California declined since 1997 from 622 metric tons to almost one third through the last thirteen years, in a relatively stable harvest. The fishery employs 294 fishermen, with annual profits of $243,000 used. The goal of the study was to assess the stock biomass, the socioeconomic performance of the fishery, and to evaluate harvesting scenarios. A relative constancy of fishing mortality (F) and the stock biomass were observed the last thirteen years. Current profits per fisher are near the maximum the fishery can produce, which is profitable under a narrow combination of age of first catch and F. Fishermen seem to avoid unprofitable activity when fishing intensity increases, so there is an apparent tendency to reduce economic risk by exerting a low effort. Immature animals are exploited, but under the low F applied, the stock can withstand it without showing signs of depletion.
Skarbnik Lopez J.,Autonomous University of Baja California Sur |
Herrero Perezrul D.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Reyes Bonilla H.,Autonomous University of Baja California Sur |
Garcia Dominguez F.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Turrubiates Morales J.,Centro Regional Of Investigacion Pesquera
Echinoderms: Durham - Proceedings of the 12th International Echinoderm Conference | Year: 2010
The reproductive cycle of Holothuria (Selenkothuria) lubrica was monitored from November 2003 to November 2004. A total of 1438 specimens were weighted and measured and the gonad of 390 individuals were preserved for the reproduction analysis. The mean length and weight were 9.69±0.070cm and 18.25 ± 0.271 g respectively. The result showed that the species grows allometrically (b = 2.072) at the study site. Five gonadal stages were described according to cell types present in the gonad: undetermined, gametogenesis, maturity, spawning and spent. Gonad index was estimated monthly and compared to gonadal stages and sea-surface temperature in order to determine if there was a relationship between these parameters. This holothurian is dioecious and sex ratio was not different from 1:1. The reproduction showed an annual pattern with a single spawning period during summer. The gonad index showed the highest values during summer, coinciding with mature gonads and when the sea-surface temperature reached its maximum. The calculated weight at first maturity was 27.3 g. © 2010 Taylor & Francis Group.
Vergara-Rodarte M.A.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Hernandez-Carmona G.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Rodriguez-Montesinos Y.E.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Arvizu-Higuera D.L.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
And 2 more authors.
Journal of Applied Phycology | Year: 2010
Gracilaria vermiculophylla, from Baja California Sur, Mexico, was studied in order to determine the seasonal variation of yield and quality of native and alkaline agar during 2007-2008. The highest alkaline agar yield was obtained in summer (17%) and the highest gel strength in spring (1,132 g cm-2). The highest melting temperature was 98°C (winter). The highest gelling temperature was 68°C (summer). The values obtained are within the range of the most important Gracilaria species harvested worldwide. During the agar extraction step, the best results were obtained after 30 min of alkali treatment with sodium hydroxide (7%), after which the quality decreased significantly. We produced Colagar from G. vermiculophylla which consists of the seaweeds treated with sodium hydroxide and dried. The yield and quality of the agar obtained from the Colagar shows stability in both yield and quality during 1 year of storage, suggesting that alkali treatment is a good method of avoiding agar hydrolysis during storage. © 2010 Springer Science+Business Media B.V.
Lopez-Fuerte F.O.,Autonomous University of Baja California Sur |
Siqueiros-Beltrones D.A.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Marine Biodiversity Records | Year: 2013
The first list of epiphytic diatom species on the seagrass Thalassia testudinum from the Yalahau lagoon area in the Mexican Caribbean is given. One hundred and seven diatom taxa living on T. testudinum were identified including species and varieties. Nine taxa are new records for Mexico. The Bacillariophyceae with 87 taxa were the most diverse group. The most abundant taxa were: Cocconeis lineata, Mastogloia crucicula var. crucicula, Cocconeis thalassiana, Cocconeis scutellum var. scutellum and Mastogloia ovata, representing approximately 75% of the total valve count (N = 1527). Yalahau lagoon samples from site 1 yielded a high number of rare taxa. Species richness (S), diversity (H′, 1-λ) and equitability (J′) for the lagoon were lower than for Cabo Catoche (site 2). Based on presence/absence of species, the measured similarity (60%) suggests that the diatom assemblages growing on T. testudinum in the two localities are different. © Marine Biological Association of the United Kingdom 2013.
Aguila-Ramirez R.N.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Arenas-Gonzalez A.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Hernandez-Guerrero C.J.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
Gonzalez-Acosta B.,Centro Interdisciplinario Of Ciencias Marinas Ipn |
And 4 more authors.
Hidrobiologica | Year: 2012
Six species of common seaweed extracts were tested in laboratory assays: Dictyota flabellata, Padina concrescens, Laurencia johnstonii, Gymnogongrus martinensis, Ulva lactuca and Codium fragile for potential industrial applications through evaluation of the antibacterial activity against pathogenic bacteria (5 strains) and the antifouling potency against the growth of key species of marine colonisers (7 bacteria, 5 fungi and 11 microalgae). The organic extract of L. johnstonii, U. lactuca and D. flabellata have bacterial antibiosis. The ethereal extracts were more active in comparison with buthanol extracts against the bacterial strain Staphylococcus aureus. The best antifouling results were obtained with U. lactuca and L johnstonii (0.1-1 μg ml-1) againstall strains tested. C.fragile exhibited significant antifouling activity with minimum inhibitory concentration (MIC) between 1-10 μg ml-1 against marine microalgae Rhodosorus magnei, Neorhodella cyanea and Prymnesium calathiferum.
Valdez-Zenil J.,University of Veracruz |
Valdez-Zenil J.,Colegio de Mexico |
Rodiles-Hernandez R.,Colegio de Mexico |
Gonzalez-Acosta A.F.,Colegio de Mexico |
And 3 more authors.
Journal of Applied Ichthyology | Year: 2014
This study examines the length-weight (L-W) and length-length (L-L) relationships, gonadosomatic indices, and size at sexual maturity for individuals of the endemic Mexican mojarra, Eugerres mexicanus (Steindachner, 1863) from the Usumacinta River Basin, Tabasco, Mexico. From April 2008 to January 2010, 360 specimens were examined, including 151 (41.9%) male, 179 (49.7%) female and 30 unsexed (8.3%) individuals. Overall female:male ratio was 1.2 : 1. Gonadosomatic index (GSI) values indicate increased reproductive activity during February, with significant differences between males (GSI = 2.07) and females (GSI = 5.48). The mean size at first maturity (L50) was 17.3 cm TL for males and 20.5 cm TL for females. © 2013 Blackwell Verlag GmbH.