Long-distance (>40-km) dispersal from marine reserves is poorly documented; yet, it can provide essential benefits such as seeding fished areas or connecting marine reserves into networks. From a ...meta-analysis, we suggest that the spatial scale of marine connectivity is underestimated due to the limited geographic extent of sampling designs. We also found that the largest marine reserves (>1000km2) are the most isolated. These findings have important implications for the assessment of evolutionary, ecological, and socio-economic long-distance benefits of marine reserves. We conclude that existing methods to infer dispersal should consider the up-to-date genomic advances and also expand the spatial scale of sampling designs. Incorporating long-distance connectivity in conservation planning will contribute to increase the benefits of marine reserve networks.
Marine dispersal distance estimates are limited by the spatial scale of sampling design and therefore biased downwards.
Active larval behavior, oceanographic eddies and fronts, tsunamis, marine debris, and translocations are potentially important, but overlooked, dispersal vectors over long distances.
The largest marine reserves have the highest potential for massive and long-distance benefits but are the most isolated reserves.
Long-distance dispersal has important consequences for the design of marine reserve networks.
Increasing human pressure has strongly impacted the littoral environment, altering the habitats and population parameters of some species. The Mediterranean Sea is one of the regions that have been ...highly affected by these events. In response to these events, marine protected areas (MPAs) have emerged as one of the main conservation tools for marine habitats and species. In this regard, harvesting of limpets (
Patella
spp.) is a good example of the impact of human activity on the coast. Limpets are mollusks that are collected as food or fishing bait, and their exploitation causes an immediate decrease in the density and size structure of individuals. In the Mediterranean Sea, the genus
Patella
is represented by five species:
Patella rustica
,
P. caerulea
,
P. ulyssiponensis
,
P. ferruginea
, and
P. depressa
. To verify the effectiveness of the MPAs, a deep review of 75 studies on
Patella
spp. in the Mediterranean Sea was conducted to analyze the spatial and temporal distribution of studies. Data extracted from these articles were used to assess the effect of protection on the density and size of
P. ferruginea
. Regarding spatial distribution, the studies reviewed were performed at 67 sites in 13 countries, of which 23 were in MPAs and 44 in non-protected or control areas. The findings of this study show that
P. ferruginea
is the species most studied, because it is one of the most threatened marine invertebrates in the Mediterranean Sea. This explains the temporal distribution of the studies, which coincides with the establishment of the conservation status and the concern about the population status of
P. ferruginea.
Analysis of the effect of protection on the density and mean size of
P. ferruginea
individuals revealed no significant difference in mean density between the control sites and MPAs. However, mean size between individuals was significantly higher in MPAs than control sites. This pattern may be related to intra- and interspecific competition between individuals.
Coastal marine lagoons are environments highly vulnerable to anthropogenic pressures such as agriculture nutrient loading or runoff from metalliferous mining. Sediment microorganisms, which are key ...components in the biogeochemical cycles, can help attenuate these impacts by accumulating nutrients and pollutants. The Mar Menor, located in the southeast of Spain, is an example of a coastal lagoon strongly altered by anthropic pressures, but the microbial community inhabiting its sediments remains unknown. Here, we describe the sediment prokaryotic communities along a wide range of environmental conditions in the lagoon, revealing that microbial communities were highly heterogeneous among stations, although a core microbiome was detected. The microbiota was dominated by
Delta
- and
Gammaproteobacteria
and members of the
Bacteroidia
class. Additionally, several uncultured groups such as
Asgardarchaeota
were detected in relatively high proportions. Sediment texture, the presence of
Caulerpa
or
Cymodocea
, depth, and geographic location were among the most important factors structuring microbial assemblages. Furthermore, microbial communities in the stations with the highest concentrations of potentially toxic elements (Fe, Pb, As, Zn, and Cd) were less stable than those in the non-contaminated stations. This finding suggests that bacteria colonizing heavily contaminated stations are specialists sensitive to change.
The daily variation of fishing effort and ex-vessel price was analysed to determine which day of the week is suitable to ban the fishery, as an alternative management measure to the one month ...seasonal closure. Thus, 10-years landings data were used from two representative trawling ports of the western Mediterranean: Dénia and La Vila Joiosa. Analysis of variance (ANOVA) was used to detect significant differences in fishing effort (total and by métier) and daily ex-vessel price of the main target species. Also, the economic loss produced by banning one day (the proposed measure) was compared to economic loss produced by the seasonal closure (the actual measure). Daily variation in the fishing effort was observed in La Vila Joiosa mainly due to higher effort at the end of the week devoted on crustacean métiers, while effort was similar among days in Dénia. The lowest mean prices for most target species were on Tuesday and Wednesday, and were higher on Monday and Friday. Banning one day per week (Tuesday or Wednesday), when market prices of target species are lower would reduce the double of effort than one month of seasonal closure, and likely without subsidies. However, the loss by banning all Wednesdays (approx. 50 days) was higher in both ports than one month, but lower than an equivalent two months closure.
•Effort variation was due to higher effort at the end of the week devoted on crustacean.•Lowest prices were on Tuesday and Wednesday, and higher on Monday and Friday.•Banning one day per week would reduce revenues less than a month of closure.•Banning one day per week would reduce the double effort than a month of closure.
The use of marine protected areas can be an effective way to simultaneously achieve both conservation and fisheries management objectives. The creation of marine protected areas, in addition to many ...benefits, also entails several costs, including the need for financing to maintain adequate surveillance and conservation. The recent economic crisis significantly lowered budgets for the maintenance of Spanish Marine Protected Areas, that may have had serious consequences for the marine resources sustainability. In this study we evaluated the indirect impact of the 2008 economic crisis on the conservation of fish stocks in Marine Protected Areas. We compared the number of species, abundance and biomass levels of the ichthyofauna, and abundance and biomass of selected species in two marine reserves (Cabo de San Antonio and Tabarca Island) with control areas, two years before (2008 and 2010) and two years after (2014 and 2015) the budget cut. Results in San Antonio revealed a decrease in total abundance, total biomass and number of species after the crisis, which translates into a decrease in the reserve effect. While in Tabarca no reduction has been observed in these variables, so the reserve effect was maintained after the crisis. We have found that of the 18 species analyzed, in San Antonio the abundance and biomass of 8 and 6 species respectively have decreased after the crisis, while in Tabarca the abundance and biomass of 6 and 8 species respectively have decreased after the crisis. Therefore, surveillance in marine reserves is necessary for the conservation of the species.
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•Factors shaping non-indigenous species (NIS) richness are tested in the Mediterranean.•There is a higher trend of NIS richness going from east to west in the Mediterranean.•NIS ...richness in marinas is mainly influenced by proximity to other major vectors.•NIS similarities between marinas are more influenced by environmental factors.•The Suez Canal exerts a very strong influence for NIS in Mediterranean marinas.
Despite the Mediterranean being both a hotspot for recreational boating and for non‐indigenous species (NIS), no data currently exists on the recreational boating sector's contribution to the spread ...of NIS in this Sea.
To improve the basis for management decisions, a wide‐scale sampling study on the biofouling communities of recreational vessels and marinas was undertaken. Specifically, we surveyed over 600 boat owners and sampled the same boat hulls for NIS in 25 marinas across the Mediterranean, from France to Cyprus, to determine which factors (i.e. boat characteristics, travel behaviour, home marina) are associated with higher NIS richness on boat hulls.
Among the surveyed boats, we found recreational vessels to travel considerably, averaging 67 travel days and 7.5 visited marinas per annum. This results in a high potential for spreading NIS, especially as 71% of sampled vessels host at least one (and up to 11) NIS. Boats with high NIS richness strongly correlate with home marinas with high NIS richness. Over half of the vessels were carriers of NIS which were not yet present in the marinas they were visiting. The presence of biofouling in niche areas of the hull (i.e. in the cavities and metallic parts) emerges as the best predictor for NIS richness on boats, along with longer times since their last cleaning and antifouling applications. Interestingly, colonization of NIS occurred rapidly, even on boats that had recently had their hulls cleaned professionally.
Synthesis and applications. We demonstrate that recreational boating has a very high capacity for the spread of non‐indigenous species (NIS) in the Mediterranean, due to both high NIS richness on boats and extensive travel. To counteract the spread of NIS, routine monitoring for new NIS needs to be established for both marinas and vessels, along with frequent pontoon cleaning. Additionally, policy should require preliminary screenings for incoming vessels from new countries, especially those emanating from high‐risk marinas. The niche areas of the boat hulls should be checked first for biofouling, which was the best predictor for NIS richness since they often go overlooked with in‐water cleanings are rarely have antifouling applied to them.
We demonstrate that recreational boating has a very high capacity for the spread of non‐indigenous species (NIS) in the Mediterranean, due to both high NIS richness on boats and extensive travel. To counteract the spread of NIS, routine monitoring for new NIS needs to be established for both marinas and vessels, along with frequent pontoon cleaning. Additionally, policy should require preliminary screenings for incoming vessels from new countries, especially those emanating from high‐risk marinas. The niche areas of the boat hulls should be checked first for biofouling, which was the best predictor for NIS richness since they often go overlooked with in‐water cleanings are rarely have antifouling applied to them.
The environmental impact of desalination is the most important concern related to its sustainable development. We present the results of a long-term environmental plan to monitor brine discharge (BD) ...from a desalination plant located in a high environmental value area in Spain. Generalized additive models were used to analyze the biological parameters of biological communities. Results of 17 years of BD monitoring show how its environmental impact can be minimized through well-planned decision-making between scientists and industry. The brine dilution prior to its discharge into an artificial channel of low ecological value significantly reduced the brine influence area. P. oceanica shoot production and echinoderms abundances were relatively stable across historical series and similar values in control and impacts locations were observed. Conversely, there was a higher abundance and species richness of fishes in the BD area. The important findings reported here should be considered for future applications in similar projects.
•A 17-year-long effluent monitoring in high-value area is presented.•Seawater bypassing effective to dilute the brine discharge•Long-term monitoring demonstrates no impact on marine ecosystems.•Higher abundance and diversity of fish were observed in brine discharge area.•Cooperation between environmental scientist and industry for sustainable SWRO
Marine reserves are being established worldwide to conserve and manage marine resources, and are also often assumed to conserve the evolutionary potential of marine populations. However, comparisons ...of genomic patterns inside and outside marine reserves in multiple species are scarce. Here, we aim to fill this gap by 1) comparing genomic variation in protected versus unprotected areas in a network of eight reserves in the Mediterranean Sea, and 2) disentangling the effect of seascape, space and marine reserves on this genomic variation in 1297 individuals from four species genotyped at more than 10 000 SNPs each. We report homogeneous patterns of local genetic diversity within and outside reserves in three of the four species (the white seabream Diplodus sargus, the striped red mullet Mullus surmuletus and the European spiny lobster Palinurus elephas). Surprisingly, the comber Serranus cabrilla shows lower genetic diversity in protected areas, highlighting an apparent conservation paradox that may be due to increased predation by protected fishes in the reserves. Multivariate analyses reveal that seascape factors (salinity, temperature and chlorophyll) and space exert a significant influence on genomic variation in some cases, while protection status has no detectable effect. Nevertheless, four marine reserves (Cabo de Palos, Cerbère‐Banyuls, Cap de Creus and Illes Columbretes) harbor singular genetic variation in one or two species. This pattern, observed in the four species, suggests that reserves contribute to preserve genetic variation locally. Our study illustrates that we can document key aspects of the genetic variation of marine species and their interaction with seascape factors, space and protection status in multiple species. It stresses the need for a multi‐species approach to inform marine conservation planning, opening up new perspectives at the community level.
In input-controlled multi-specific fisheries, seasonal closure has little biological rationale as a management measure, because it is difficult to adjust such closure for many target species and, in ...most cases, they are adopted for economic purposes. We aimed to determine effects of closure in biologic and economic terms, using 10-year landing data from two representative trawling ports of the Western Mediterranean: Dénia and La Vila Joiosa. Analysis of Variance (ANOVA) was used to detect significant differences, before and after the closure, in standardized catch per unit effort (CPUE) at different seasons and sale prices at home/closed and neighbour/open ports. ANOVAs showed significantly higher CPUE after the closure for total landings and Mullus spp. of the Red mullet métier, Merluccius merluccius CPUE (in two years) and the total landings of the Norway lobster métier. On the contrary, significant lower values were observed after the closure for total CPUE (in early summer) and Aristeus antennatus of Red shrimp métier. Similar CPUE was observed at all levels when the closure took place in late summer. In economic terms, market prices of target species have decreased or shown no changes after the closure at home/closed and neighbouring/open ports. The only exception was the significant increase of the price for A. antennatus in Dénia during the closure in La Vila Joiosa. Depending on its timing, the closure would highlight some positive biological effects on some target species. However, closure leads to an unavoidable reduction in most of target species prices. An alternative management measure that is based on effort reduction in input-controlled multi-specific fisheries could ban one day per week when market prices of target species are lower.
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