The invasion rate of the eastern Mediterranean by new Red Sea fishes (Lessepsian migrants) has accelerated in recent years. It was estimated by Ben-Tuvia (1985) that during the years 1950-1983, an average of 1.2 Red Sea fish species followed the Suez Canal into the Mediterranean each year. Since 1987 six species (Golani and Ben-Tuvia, 1989;Golani, 1992), as well as the two reported herein, have been added to the list of Lessepsian migrant fishes.On July 16, 1991, a 52.1mm SL specimen of Pteragogus pelycus was collected in Haifa Bay by the second author, on board the trawler F/V Nitzan Capt. Z. Havushi, from a catch trawled from a depth of 32 to 80m. An additional 60.5mm SL specimen was collected on the same ground the following day.On July 28, 1991, a 328mm SL specimen of Pterois miles was landed by the trawler F/V Galdag, Capt. L. Ornoy, from a depth of 35m near Herzliya, Israel, 10 km north of Tel-Aviv. The specimen was presented fresh to the first author at the fishing harbor of Ashdod.The specimens of the new migrants were deposited in the Hebrew University of Jerusalem fish Collection (HUJ), where they were compared to conspecific Red Sea specimens. The descriptions refer to the Mediterranean specimens, followed by numbers in parenthesis for the compared Red Sea specimens.

Recent decades have seen profound changes in species abundance and community composition. In the marine environment, the major anthropogenic drivers of change comprise exploitation, invasion by nonindigenous species, and climate change. However, the magnitude of these stressors has been widely debated and we lack empirical estimates of their relative importance. In this study, we focused on Eastern Mediterranean, a region exposed to an invasion of species of Red Sea origin, extreme climate change, and high fishing pressure. We estimated changes in fish abundance using two fish trawl surveys spanning a 20-year period, and correlated these changes with estimated sensitivity of species to the different stressors. We estimated sensitivity to invasion using the trait similarity between indigenous and nonindigenous species; sensitivity to fishing using a published composite index based on the species' life-history; and sensitivity to climate change using species climatic affinity based on occurrence data. Using both a meta-analytical method and random forest analysis, we found that for shallow-water species the most important driver of population size changes is sensitivity to climate change. Species with an affinity to warm climates increased in relative abundance and species with an affinity to cold climates decreased suggesting a strong response to warming local sea temperatures over recent decades. This decrease in the abundance of cold-waterassociated species at the trailing "warm" end of their distribution has been rarely documented. Despite the immense biomass of nonindigenous species and the pre-

SUMMARY:The spatiotemporal patterns of discards and catch composition of Israeli trawlers were examined using a 4-year (1990-1994), 324 haul dataset. Haul depth was found to be the main grouping variable for hauls, although significant seasonal differences were also found. 28.3% of the total catch was discarded, and there was a 40.1% discard percentage in shallow hauls. According to these figures, annual discards for the Israeli trawl fleet for the study period are estimated at ca. 440 to 700 t. Both the biomass and the number of discarded specimens peaked in summer, as well as the percentage of juvenile fish of commercial species. These findings suggest that a summer moratorium on trawling would reduce discards. The percentage of specimens of Indo-Pacific origin decreased from 51% in depths shallower than 37 m to 24% between 38 and 73 m, and 8% in deeper strata. Discards along the Israeli coast were comparable to those observed elsewhere in the Mediterranean. The findings presented here are the first quantitative account of fish community assemblages in the nearshore waters of the easternmost part of the Mediterranean, and thus provide valuable information for comparisons with more current datasets that are currently being assembled.Keywords: bottom-trawl, Israel, discards, catch composition, Lessepsian migration, fishery management. RESUMEN:Patrones espacio-temporales de la captura y los descartes de pesquería de arrastre mediterránea israelí al inicio de la década de los noventa: perspectivas ecológicas y de conservación. -Se analizaron los patrones espacio-temporales de los descartes y la composición de la captura de la flota de arrastre de Israel utilizando datos de 4 años (1990)(1991)(1992)(1993)(1994), 324 caladas. La profundidad resultó ser el principal factor en la agrupación de las caladas, si bien se encontraron asimismo diferencias significativas entre estaciones. Se descartó el 28.3% de la captura total, alcanzándose el 40.1% en las caladas realizadas en las aguas más someras. Según estos porcentajes, se estimó una captura anual descartada por la flota de Israel en ese período de 440-700 t. La biomasa, el número de ejemplares descartados, así como el porcentaje de juveniles de especies comerciales fue mayor en verano. Estos resultados sugieren que una veda de arrastre en verano favorecería la disminución de la captura descartada. El porcentaje de ejemplares de origen indo-pacífico descendió desde 51% en aguas de una profundidad inferior a 37 m, al 24% entre 38-73 m y al 8% en el estrato más profundo. Los descartes en la costa israelí fueron similares a los observados en otras zonas del Mediterráneo. Se presentan por primera vez resultados cuantitativos relativos a comunidades de las aguas costeras del extremo oriental del Mediterráneo, aportándose información para su comparación con datos más recientes que en la actualidad están siendo obtenidos.Palabras clave: arrastre de fondo, Israel, descartes, composición de la captura, migración lessepsiana, gestión de pesquerías.

Marine biota are redistributing at a rapid pace in response to climate change and shifting seascapes. While changes in fish populations and community structure threaten the sustainability of fisheries, our capacity to adapt by tracking and projecting marine species remains a challenge due to data discontinuities in biological observations, lack of data availability, and mismatch between data and real species distributions. To assess the extent of this challenge, we review the global status and accessibility of ongoing scientific bottom trawl surveys. In total, we gathered metadata for 283,925 samples from 95 surveys conducted regularly from 2001 to 2019. We identified that 59% of the metadata collected are not publicly available, highlighting that the availability of data is the most important challenge to assess species redistributions under global climate change. Given that the primary purpose of surveys is to provide independent data to inform stock assessment of commercially important populations, we further highlight that single surveys do not cover the full range of the main commercial demersal fish species. An average of 18 surveys is needed to cover at least 50% of species ranges, demonstrating the importance of combining multiple surveys to evaluate species range shifts. We assess the potential for combining surveys to track transboundary species redistributions and show that differences in sampling schemes and inconsistency in sampling can be overcome with spatio‐temporal modeling to follow species density redistributions. In light of our global assessment, we establish a framework for improving the management and conservation of transboundary and migrating marine demersal species. We provide directions to improve data availability and encourage countries to share survey data, to assess species vulnerabilities, and to support management adaptation in a time of climate‐driven ocean changes.

The gradient of environmental conditions from west to east in the Mediterranean results in very low primary productivity in the eastern area of this sea. This impoverishment is expressed also in higher trophic levels and has been accounted for by several faunistic phenomena. One of these is 'Levantine nanism' (dwarfism); this is characterized by smaller body size of specimens in the Levantine basin compared with conspecifics in the western Mediterranean. Nanism has been hypothesized for various taxonomic groups in the Mediterranean, but no quantitative study has yet been carried out to confirm it. In the present study male and female red mullet Mullus barbatus from trawl surveys carried out along the Mediterranean coast of Israel and the Strait of Sicily were sampled. Each fish was sexed, measured for total length (TL) and aged by otolith readings. ANCOVA analyses indicated that the TL of both males and females from Israel was significantly smaller at increasing ages than conspecifics of the same age and sex from Sicily. In addition, preliminary examination of sexual maturity of M. barbatus of both sexes indicated that the Israeli fish sexually mature at a smaller size than conspecifics of the same sex from Sicily. These findings can be explained by low productivity in the Levantine basin compared with the western Mediterranean. The low and unpredictable food supply in the southeastern Mediterranean may result in a form of r-strategy of the marginal eastern populations of this species that leads to early reproduction and smaller body size. The average higher water temperature may also partly explain Levantine nanism, as it may cause more intensive metabolic processes in the southeastern population, resulting in earlier sexual maturity and cessation of growth.