Portuguese Artisanal Fishers’ Knowledge About Elasmobranchs—A Case Study

The high economic value of fisheries was historically associated to commercial teleost fishes. Since the 1970s, despite some elasmobranchs becoming an important target or a bycatch, relatively little research has been carried out on this group because of their low economic value. Due to their specific life history characteristics, sharks and rays are particularly vulnerable to overexploitation, taking several decades to recover after reaching an overexploitation status. In Portugal elasmobranch fishery results mainly from targeted longlining and bycatch from different fishing gears. During the last decade, the Total Allowable Catches (TACs) of rays have been decreasing, the European Union (EU) banned the capture of some ray species, the Portuguese government implemented both a closed season and a minimum landing size for some rays, and the EU prohibited target fishing for sharks. All these measures may have been highly responsible for the national and local landings reduction. Official landings from the last decade were analyzed, the landed species conservation status was consulted, and structured interviews using a questionnaire were conducted in the most important fishing port in the Portuguese mainland, the port of Sesimbra. Results led us to conclude that fishers’ answers and landings data did not match. It also revealed a lack of awareness by fishers about the state of shark and ray populations, and about some aspects of their biology and ecology, like reproduction season and method. The present study highlights the need to fill in this existing gap in knowledge through the transfer of scientific knowledge and sharing of management responsibilities. Also, we aimed to demonstrate the necessity for awareness and education activities within fishing communities, an essential step to elasmobranch conservation.

Variation in size distribution of juvenile pink shrimps Farfantepenaeus brasiliensis and F. paulensis in the estuarine-adjacent ocean area of Cananéia, south-eastern coast of Brazil

The study characterized the structure of juveniles and sub-adults of Farfantepenaeus brasiliensis and F. paulensis in the Cananéia-Iguape estuarine lagoon system and its adjacent coastal area by evaluating the period of juvenile recruitment, sex ratio, growth, longevity, natural mortality, and development time until the late juvenile phase. Samples were collected from July 2012 to June 2014. Shrimps were identified by species and sex, and measured (carapace length – CL mm); 889 individuals of F. brasiliensis and 848 of F. paulensis were analysed. Females were more abundant than males for both species. The growth parameters of F. brasiliensis were: CL∞ = 45.5 mm, k = 1.8 year−1 for males and CL∞ = 55.2 mm, k = 1.6 year−1 for females; longevity of 2.52 years (males) and 2.88 years (females); and natural mortality of 1.71 (males) and 1.55 (females). For F. paulensis, the following values were observed: CL∞ = 40.7 mm, k = 2.3 year−1 for males and CL∞ = 56.5 mm, k = 1.9 year−1 for females; longevity of 2.04 years (males) and 2.37 years (females); and natural mortality of 2.39 (males) and 2.05 (females). The juvenile recruitment of both species peaked in January 2014. The development time until late juvenile phase was ~7 months (F. brasiliensis) and ~5 months (F. paulensis). Even though the highest abundance of juveniles did not occur in the closed season, fishing is forbidden in the estuarine area and the migration towards the adult population occurred close to or even during the closed season.

Towards the rebuilding of spiny lobster stocks in Brazil: a review

In this study, we used the Monte Carlo model (CMSY) to estimate fisheries reference points based on annual lobster landings. During the period 2012-2018, fishing pressure on lobster stocks decreased and a tendency for recovery was observed, despite the low biomass levels of approximately 29%. In 2019, the stock size was capable of producing yields close to the maximum sustainable yield (5770 t), with a probability of 58.1%. The enforcement of management measures should be continued in order to eliminate sources of negative externalities and rebuild stocks. We also demonstrate that the closed season does in fact protect the main events of the lobster life cycle. Responsible and efficient management should focus on life cycle studies and reliable monitoring of fishing data.

The monsarás District community on the island of marajó: Its affinity with artisanal fishing and the environment

Artisanal fishing is an activity of great importance in Brazil and the Amazon, mainly for the generation of income and source of subsistence. The objective of this research is to characterize the artisanal fisheries of the Monsaráscommunity on Ilha do Marajó and to identify the relationships between these activities and factors related to the environment. The methodology was based on the application of a questionnaire to artisanal fishermen in this community and to carry out local observations. The results show that fishing in Monsarás is carried out throughout the year, from Monday to Friday and can last 6, 12 and even 24 hours a day. The species of greatest value and the most caught are the yellow hake (Cynoscionacoupa) and the golden hake (Brachyplatystomarousseauxii). Labor relations take place through the partnership system and the production of fish is traded in the community itself or to a middleman who works at the place that resells the fish, mainly in the Ver-o-peso market in Belém. Environmental laws known in Monsarás are those related to compliance with the rules of the closed season. Artisanal fishing is characterized by an activity that requires few fishing gear, small vessels and that cause low environmental impact.

Population trends of beach-spawning California grunion Leuresthes tenuis monitored by citizen scientists

California Grunion Leuresthes tenuis (Atherinopsidae), an indigenous endemic marine fish, makes spectacular midnight spawning runs onto sandy beaches on the Pacific coast of California and Baja California. In a unique recreational fishery, people capture the fish out of water with bare hands. Grunion hunters are not required to report their catch, and there is no bag limit. California Grunion rarely appear in trawls and do not take a hook, so population status for this species is impossible to obtain by traditional fishery methods. With citizen scientists, the “Grunion Greeters,” we monitored spawning runs along most of their habitat range. California Grunion recently underwent a northward range extension, but runs appear to be declining broadly across the core habitat. Noisy activities of recreational grunion hunters on shore disrupt spawning runs, preventing fish from reproducing before capture. Leuresthes tenuis has been identified as a Key Indicator Species for the South and Central regions of California Marine Protected Areas, and as an indicator species for climate change on beaches. Gear restrictions, license requirements, and a two-month closed season are rarely enforced late at night. We recommend continued monitoring for L. tenuis in California and increased protections for this unique charismatic fish.

Age, Growth and Gonado-somatic Index of the Red Mullet (Mullus barbatus ponticus Essipov, 1927) in the Eastern Black Sea coast of Turkey

In this study, the age, growth, and gonado-somatic index (GSI) of the Red mullet (Mullus barbatus ponticus Essipov, 1927) from the Eastern Black Sea coast of Turkey were examined. A total of 1466 M. barbatus ponticus were sampled between September 2010 and August 2011 from trammel net landings in Rize. The total length of Red mullet ranged from 7.42 cm to 17.80 cm and weight ranged from 9.59 g to 50.93 g, regardless of the sex. The sex ratio (♂/♀) was 0.46, with almost twice more females than males. The growth performance of M. barbatus ponticus in the study area is similar to that of the western populations of the same sub-species. A closed season of at least three months (from May to July) banning the use of even the stationary fishing gear will be beneficial for the sustainable stock of management of M. barbatus ponticus in the Black Sea.

Filling biological information gaps of the marine topshell Phorcus sauciatus (Gastropoda: Trochidae) to ensure its sustainable exploitation

Topshells play a pivotal role in intertidal rocky ecosystems and are adapted to harsh thermal and hydric stress. Phorcus sauciatus, a common grazer in the Macaronesian region (Madeira and the Canaries), has rarely been studied due to its restricted geographic distribution compared with Phorcus lineatus. Monthly samples were taken throughout 2017 to analyse biological parameters and evaluate the harvesting effect on the stocks of this species in Madeira. Individuals of the first age classes (<4 years) were dominant (~89%), while immature individuals were more abundant during the summer season. The spawning season occurs between March and August, especially from March to June. The size at first maturity was 12.95 mm long (1.68 years), with a continuous recruitment pattern throughout the year. Yield-per-recruit analysis (Y/R) showed that maximum production is achieved at a fishing mortality of 1.7 year−1, corresponding to a Y/R of 0.023 g. Currently, Phorcus sauciatus seems to be moderately exploited in Madeira, but urgent conservation measures, such as a landing obligation, the establishment of a minimum catch size of 15 mm length, and a closed season (February–May), are warranted to preserve stocks of this species in the medium to long term.