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This study evaluates the link between sea warming and three important aspects of the population dynamics of bluefish, Pomatomus saltatrix, in the north‐western (NW) Mediterranean: condition (health measures), reproduction and abundance (as reflected in catch per unit effort, CPUE). We compared the bluefish populations from two areas with different thermal regimes: the Gulf of Roses and the Ebre Delta. First, in order to compare the condition and reproduction parameters of the two populations, specimens were collected from the commercial catch landed in two ports located in these areas. Several indicators of fish condition and reproduction such as hepatosomatic index, gonadosomatic index, maturation timing, length‐at‐first maturity, fecundity, egg quality and atresia (ovarian follicle resorption) were analysed and compared between study areas. Second, time series analyses of sea surface temperatures (SST) and monthly bluefish CPUEs in the two study areas were assessed using Box–Jenkins transfer function models. Our results indicate that bluefish benefit from sea warming in the NW Mediterranean, particularly in the northernmost zone, as evidenced by increasing fish condition in these waters. Sea warming may favour the changes in spawning phenology and the northward expansion of this species. This study provides evidence that a marine fish species that is able to expand or is forced to shift its distribution as a result of sea warming may take advantage of other environmental conditions of new habitats, contributing to the enhancement of the population's productivity in these areas.

This study indicated that the life-history traits of European barracuda Sphyraena sphyraena are apparently better suited to their environmental conditions compared to the more physically restricted life-history traits of the yellow-mouth barracuda Sphyraena viridensis, which co-habit the north-western Mediterranean Sea. The latter thermophilic species has a considerably higher reproductive potential as it invests its energy reserves in larger numbers of hydrated eggs per spawning batch. This would favour its population growth rates within the study area, especially if sea warming continues, in which case it is likely that the spawning phenology of this species would give it an advantage.

This study describes for the first time the reproductive traits of the warm-water pompano, Trachinotus ovatus. Specimens were sampled from landings by artisanal fishing vessels in the NW Mediterranean. Monthly collections, from July 2010 through to September 2012, yielded 226 individuals (118 females and 108 males). The size at 50% maturity (L 50 ) was estimated at 30.9 and 29.1 cm TL for females and males, respectively. Specific reproductive traits, such as oocyte size-frequency distributions, presence of recent post-ovulatory follicles along with oocytes in the final phases of gonadal development, and massive atresia in post-spawning individuals, indicated that pompanos are multiple batch spawners with asynchronous oocyte development and indeterminate fecundity. Monthly variations in the gonadosomatic index and in the phases of gonadal development indicated July and August as the spawning season. There were also noticeable inter-annual variations in spawning phenology, mean diameters of the oocytes, relative batch fecundity and eggs quality, all of which corresponded to changes in sea surface temperatures. This study enhances our understanding of the need for research into the reproduction of warm-water species, which are currently expanding into the increasingly warmer waters of the world's more northerly seas and oceans. -M. (2013) Trophic structure in the Gulf of Lions marine ecosystem (north-western Mediterranean Sea) and fishing impacts. Journal of Marine Systems 111-112, 45-68. Batistić M., Tutman P., Bojanić D., Skaramuca B., Kožul V., Glavić N. and Bartulović V. (2005) Diet and diel feeding activity of juvenile reproduction of t. ovatus in the nw mediterranean harold villegas-herna ' ndez et al.

This study evaluates the influence of sea water temperature on the life-history traits of the thermophilic bastard grunt Pomadasys incisus along the Catalan coast. We compared two key traits of this species, condition and reproduction, from populations in two separate areas with different thermal regimes: the Gulf of Roses (cold area) and the Ebre Delta (warm area). Specimens were collected monthly from each area between 2010 and 2012. The results were also compared with those given in the literature from sites where the species is more common, i.e. the southern Mediterranean and eastern Atlantic. Our findings indicate that, compared to the populations in warmer environments, the population inhabiting the colder waters appears to be in significantly poorer condition and there is some deviance in their life-history traits: egg size and quality being traded-off for higher egg numbers; lower lengths at maturity and alterations to spawning phenology. A certain degree of plasticity in life-history traits may favour the process of expansion and establishment of this thermophilic species into newly available but colder habitats of the north-western Mediterranean under a scenario of climate change.

Settlement dynamics of the bicolor damselfish Stegastes partitus (Pomacentridae) were determined by otolith shape and microstructure analysis and compared among different coral reef areas (Windward, Lagoon, and Leeward) of Chinchorro Bank, northern Meso-American Barrier Reef System, eastern Yucatan Peninsula. Estimated age, settlement time, size at settlement, and larval otolith growth rates were compared using a 2-way ANOVA with 2 fixed and orthogonal factors (reef areas and cays) with 3 levels each. Significant differences in planktonic larval duration were found, with (mean) 28.8, 30.3 and 32.7 d spent at Windward, Lagoon and Leeward, respectively. Individuals with shorter larval durations (at Windward) showed faster otolith growth rates and settled at relatively smaller sizes than those with longer larval durations (Lagoon and Leeward). However, there was no significant difference in otolith growth rates among reef areas, and there was no clear evidence for delay in metamorphosis. Based on both the planktonic larval duration (PLD) and the prevalent current pattern in the area, it appears that strong northwesterly currents passively transport S. partitus larvae into Chinchorro Bank. Larvae may enter at Windward, pass through the reef Lagoon, and leave by the Leeward. Longer PLD for S. partitus settling at Leeward are not due to differences in larval growth rates, but more likely to a lack of access to suitable settlement habitat by the time the larvae has passed through the reef system. An otolith shape (Fourier) analysis revealed a clear differentiation between otoliths from the 3 reef areas, suggesting that the environmental influence on otolith shape of S. partitus is relatively uniform, which means that this fish is affected by similar local environmental conditions within each reef area.

The Goliath grouper, Epinephelus itajara, a large-bodied (~ 2.5 m TL, > 400 kg) and critically endangered fish (Epinephelidae), is highly vulnerable to overfishing. Although protected from fishing in many countries, its exploitation in Mexico is unregulated; a situation that puts its populations at risk. Fishery records of E. itajara are scarce, which prevents determination of its fishery status. This work aimed to elucidate the E. itajara fishery in the northern Yucatan Peninsula by 1) analyzing available catch records and 2) interviewing veteran fishermen (local ecological knowledge) from two traditional landing sites: Dzilam de Bravo and Puerto Progreso. Historic fishery records from two fishing cooperatives were analyzed in order to elucidate the current situation and offer viable alternatives for conservation and management. Catches have decreased severely. Local knowledge obtained from fishermen represented a very important source of information for reconstructing the fisheries history of this species. Conservation measures that incorporate regional and international regulations on critically endangered fish species are suggested.

A total of 51 sponges (Porifera) and 13 ascidians (Chordata) were collected on the coast of the Yucatan Peninsula (Mexico) and extracted with organic solvents. The resulting extracts were screened for antibacterial activity against four multidrug-resistant (MDR) bacterial pathogens: the Gram-negative Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa and the Gram-positive Staphylococcus aureus. The minimum inhibitory concentrations (MICs) of the organic extracts of each marine organism were determined using a broth microdilution assay. Extracts of eight of the species, in particular the Agelas citrina and Haliclona (Rhizoniera) curacaoensis, displayed activity against some of the pathogens tested. Some of the extracts showed similar MIC values to known antibiotics such as penicillins and aminoglycosides. This study is the first to carry out antimicrobial screening of extracts of marine sponges and ascidians collected from the Yucatan Peninsula. Bioassay-guided fractionation of the active extracts from the sponges Amphimedon compressa and A. citrina displayed, as a preliminary result, that an inseparable mixture of halitoxins and amphitoxins and (-)-agelasine B, respectively, are the major compounds responsible for their corresponding antibacterial activities. This is the first report of the antimicrobial activity of halitoxins and amphitoxins against major multidrug-resistant human pathogens. The promising antibacterial activities detected in this study indicate the coast of Yucatan Peninsula as a potential source of a great variety of marine organisms worthy of further research.