Editorial: vulnerability of fisheries to climate change

Evidence that environmental and climate change (CC) cause long-term and large-scale variability in the dynamics of marine species populations is growing. This new variability, combined with the well-known impacts of fishing itself, would need to be quantified and integrated in the sustainable management of fisheries. The relative importance of fisheries and CC (e.g., warming, acidification, and sea level rise) onmarine and estuarine resources remains an issue of debate within the scientific community, the fishing sector, and the general public.PTDC/ASP-PES/28518/2017/ UID/Multi/04326/2020/ DL57/2016/CP1361/CT0008/ MAR2020-FEAMP (MAR-01.03.02-FEAMP-0052) project CLIMA-PESCAinfo:eu-repo/semantics/publishedVersio

An ecological and fishing approach to support management decisions

Leitão, F., Monteiro, J. N., Cabral, P., Teodósio, M. A., & Roa-Ureta, R. H. (2023). Revealing the role of crab as bait in octopus fishery: An ecological and fishing approach to support management decisions. Marine Policy, 158, 1-11. [105878]. https://doi.org/10.1016/j.marpol.2023.105878 --- This study received Portuguese National Funding from MAR2020 project CRUSTAPANHA (MAR-01.04.02-FEAMP-0005 CRUSTAPANHA). FL has received Portuguese national funds from FCT within the contract program DL57/2016/CP1361/CT0008 and FCT 2022.04803. CEECIND. JNM received an FCT PhD fellowship SFRH/BD/06336/2021. This study received Portuguese national funds from FCT - Foundation for Science and Technology through projects UIDB/04326/2020, UIDP/04326/2020 and LA/P/0101/2020. Authors would like to acknowledge all fishers’ associations that participated in CRUSTAPANHA project and helped the completion of the study: AAPF- Associação de Armadores e Pescadores da Fuseta (Fuseta); Associação Armalgarve Polvo Organização De Produtores (Quarteira); OLHAOPESCA Organização de Produtores de Pesca do Algarve, C.R.L. (Olhão). We acknowledge DGRM for fisheries data provided and for granting licenses for researchers onboard fishing vessel; To the coast guards forces of the following ports: Capitania do Porto de Albufeira; Capitania do Porto de Faro; Capitania do Porto de Olhão; Capitania do Porto de Lagos; Capitania do Porto de Tavira; We would like to acknowledge specific captains due to their role in the study, namely: Ricardo Santana; Francisco Molina; Arlindo da Silva Correia; Paulo Guerreiro. We would like to acknowledge all the members of ECOREACH group that help in the measurement of the octopus specimens, namely Andreia Ovelheiro, Daniela Nobre, Juan Bueno-Pardo and Miguel PintoIn southern Portugal, artisanal octopus fisheries play an important socioeconomic role. Live crab bait in traps was used up to 2010 and banned in 2012. Such regulation, based on co-management advice, was not established under a scientific fundament. As a result, a long-standing controversy ensued with some fishing associations claiming that live crab bait increased fishing effort and exploitation rates and therefore risked the octopus stock status, while other fishers denied all these alleged impacts. The issue has not been resolved so far due to lack of scientific studies. In this study, we resolve the controversy conducting experimental fishing to determine by-catch and octopus catch rates using live crab bait versus other types of baits based on fish and assess the stock status of octopus over-time with constant parameters (hypothesis of no effect of the use of live crab bait) versus time-varying parameters (hypothesis of raised exploitation rates and riskier stock status). Bycatch was very low regardless of bait type. Our experimental fishing trials showed that fish-based baits increase bycatch and octopus catch rates. Stock assessment models showed that exploitation rates and stock status do not worsen in years of use of crab bait. We conclude that the use of crab bait in octopus fishery does not lead to increased exploitation rate or risks for stock sustainability status. Other considerations involving fishing costs and fishing operations further highlight the advantages of lifting the ban on the use of live crab bait in the Algarve octopus fishery.publishersversionpublishe

A comparison of three data-poor stock assessment methods for the pink spiny lobster fishery in Mauritania

Several data-poor stock assessment methods have recently been proposed and applied to data-poor fisheries around the world. The Mauritanian pink spiny lobster fishery has a long history of boom and bust dynamics, with large landings, stock collapse, and years-long fishery closures, all happening several times. In this study, we have used catch, fishing efforts, and length-frequency data (LFD) obtained from the fishery in its most recent period of activity, 2015–2019, and historical annual catch records starting in 2006 to fit three data-poor stock assessment methods. These were the length-based Bayesian (LBB) method, which uses LFD exclusively, the Catch-only MSY (CMSY) method, using annual catch data and assumptions about stock resilience, and generalised depletion models in the R package CatDyn combined with Pella-Tomlinson biomass dynamics in a hierarchical inference framework. All threemethods presented the stock as overfished. The LBB method produced results that were very pessimistic about stock status but whose reliability was affected by non-constant recruitment. The CMSY method and the hierarchical combination of depletion and Pella-Tomlinson biomass dynamics produced more comparable results, such as similar sustainable harvest rates, but both were affected by large statistical uncertainty. Pella-Tomlinson dynamics in particular demonstrated stock experiencing wide fluctuations in abundance. In spite of uncertain estimates, a clear understanding of the status of the stock as overfished and in need of a biomass rebuilding program emerged as management-useful guidance to steer exploitation of this economically significant resource into sustainability.info:eu-repo/semantics/publishedVersio

Ecology, life history, and fisheries potential of the flathead lobster (Thenus orientalis) in the Arabian Gulf

This study, which included examination of the distribution and life history and a stock assessment of the flathead lobster (Thenus orientalis), is the first of its kind in the waters of Saudi Arabia in the Arabian Gulf, also known as the Persian Gulf. The flathead lobster is widely distributed in this region, although it is more abundant in the central and northern Arabian Gulf. Carapace lengths at 50% and 95% maturity are 59 and 65 mm for females and 58 and 71 mm for males. The fecundity of 4 berried females ranged from 26,000 to 76,000 eggs per spawning, and the fertilization rate exceeded 97%. Length-frequency data were consistent with just 2 cohorts, indicating that this species has a short life span and high growth coefficient (K=0.846 year(-1)). Large fishing boats (called dhows) accounted for more than 98% of the total landings. Estimates of natural mortality rates from use of generalized depletion models have high statistical precision and a magnitude compatible with short life history. In addition, abundance levels estimated with the depletion model are sufficient to support a sustainable small-scale fishery either as bycatch of shrimp trawlers or as a resource targeted with specialized gear. A targeted fishery for flathead lobster could be set during the off months of the shrimp trawl fishery (February-July), reducing interference with the reproduction cycle.info:eu-repo/semantics/publishedVersio

Diversity, distribution, and density of marine mammals along the Saudi waters of the Arabian Gulf: update from a multi-method approach

Despite the important role of marine mammals in marine ecosystems and the imperative for their conservation, there is still a great lack of information on the diversity, distribution, and density of these animals in the Saudi waters of the Arabian Gulf. To fill this gap, an integrative data-collection approach including fishermen’s questionnaires, opportunistic sighting reports, and directed boat-based surveys, was undertaken between 2016 and 2020, leading to the first scientific report of marine mammal diversity, distribution, and density in the region. The results of the different approaches carried out during the study confirmed a high diversity of cetaceans on the west coast of the study area, with bottlenose dolphins (Tursiops aduncus), humpback dolphins (Sousa plumbea) and dugongs (Dugong dugon) as the most common species. While the two dolphin species were found to be widely distributed in both coastal and offshore waters, D. dugon appears to occur exclusively in coastal waters in the southern part of the study area, mainly in the Gulf of Salwah. The presence of both species of dolphins increased during the summer months and in the vicinity of the numerous oil and gas facilities in this region. The distribution of the observed dolphins was found mostly within a 10–20 km radius around each facility. Other cetacean species observed less frequently in the area include Bryde’s whale (Balaenoptera edeni), killer whale (Orcinus orca), common dolphin (Delphinus delphis) and finless porpoise (Neophocaena phocaenoides). Regarding the density of marine mammals in the region, boat-based surveys confirmed the results of fishermen’s questionnaires and reports of opportunistic sightings, with bottlenose and humpback dolphins being the most abundant species. These results provide a baseline for policies oriented to the conservation of mammals in the Saudi waters of the Arabian Gulf.info:eu-repo/semantics/publishedVersio

Management for sustainable cephalopod fisheries in Europe: review and recommendations

Although cephalopod fisheries are of world-wide importance, in Europe catching cephalopods is managed only in small-scale fisheries, at national level, and few stocks are formally assessed. Because cephalopods are not quota species under the EU’s Common Fisheries Policy, there is currently no requirement for assessment or management at European level. Given increasing interest in targeting cephalopods in Europe, there is a risk that they will be fished unsustainably. Although there have been recent review papers on progress in stock assessment and fishery forecasting for commercially fished cephalopods there has been no recent review of cephalopod fishery management. We aim to fill this gap, with a particular focus on European cephalopod fisheries.We review potential barriers to sustainable fishing and reasons why management of cephalopod fisheries differs from that for finfish fisheries, e.g. due to the high inherent volatility and the possibly cyclic nature of year-to-year variation in cephalopod abundance, reflecting their short lifespan, rapid growth and high sensitivity to environmental conditions. We review fishery management approaches in important cephalopod fisheries worldwide (e.g. in the USA, Japan, Falklands, South Africa, Australia and Russia) and current management of small-scale cephalopod fisheries in Europe. We identify knowledge gaps and limitations to current monitoring programmes and stock assessments and discuss the options available for cephalopod fishery management in Europe, considering the suitability or otherwise of catch and effort limits, use of closed areas and seasons, restrictions on sizes caught and types of fishing gear, and the ole of market-based sustainability pathways.info:eu-repo/semantics/publishedVersio

Working group on cephalopod fisheries and life history (Wgceph; outputs from 2022 meeting)

Rapports Scientifiques du CIEM. Volume 5, nº 1WGCEPH worked on six Terms of Reference. These involved reporting on the status of stocks; reviewing advances in stock identification, assessment for fisheries management and for the Ma- rine Strategy Framework Directive (MSFD), including some exploratory stock assessments; re- viewing impacts of human activities on cephalopods; developing identification guides and rec- ommendations for fishery data collection; describing the value chain and evaluating market driv- ers; and reviewing advances in research on environmental tolerance of cephalopods. ToR A is supported by an annual data call for fishery and survey data. During 2019–2021, com- pared to 1990–2020, cuttlefish remained the most important cephalopod group in terms of weight landed along the European North Atlantic coast, while loliginid squid overtook octopus as the second most important group. Short-finned squid remained the least important group in land- ings although their relative importance was almost double in 2019–2022 compared to 1992–2020. Total cephalopod landings have been fairly stable since 1992. Cuttlefish landings are towards the low end of the recent range, part of a general downward trend since 2004. Loliginid squid landings in 2019 were close to the maximum seen during the last 20 years but totals for 2020 and 2021 were lower. Annual ommastrephid squid landings are more variable than those of the other two groups and close to the maximum seen during 1992– 2021. Octopod landings have generally declined since 2002 but the amount landed in 2021 was higher than in the previous four years. Under ToR B we illustrate that the combination of genetic analysis and statolith shape analysis is a promising method to provide some stock structure information for L. forbsii. With the sum- mary of cephalopod assessments, we could illustrate that many cephalopod species could al- ready be included into the MSFD. We further provide material from two reviews in preparation, covering stock assessment methods and challenges faced for cephalopod fisheries management. Finally, we summarise trends in abundance indices, noting evidence of recent declines in cuttle- fish and some octopuses of the genus Eledone. Under ToR C, we describe progress on the reviews of (i) anthropogenic impacts on cephalopods and (ii) life history and ecology. In relation to life history, new information on Eledone cirrhosa from Portugal is included. Under ToR D we provide an update on identification guides, discuss best practice in fishery data collection in relation to maturity determination and sampling intensity for fishery monitoring. Among others, we recommend i) to include the sampling of cephalopods in any fishery that (a) targets cephalopods, (b) targets both cephalopods and demersal fishes or (c) takes cephalopods as an important bycatch, ii) Size-distribution sampling, iii) the use of standardized sampling pro- tocols, iv) an increased sampling effort in cephalopod. Work under ToR E on value chains and market drivers, in conjunction with the Cephs & Chefs INTERREG project, has resulted in two papers being submitted. Abstracts of these are in the report. Finally, progress under ToR F on environmental tolerance limits of cephalopods and climate en- velope models is discussed, noting the need to continue this work during the next cycle.info:eu-repo/semantics/publishedVersio

Modelling long-term fisheries data to resolve the attraction versus production dilemma of artificial reefs

The main role of artificial reefs (ARs) is to enhance the productivity and sustainability of coastal fisheries by creating new fish biomass. From a modelling point of view, the creation of new fish biomass would be realized by a shift to a state of higher carrying capacity of the environment (K) for aquatic populations and communities. However, it has not been possible to demonstrate unequivocally rising K as a result of AR deployment because of the difficulty in disentangling enhancements due to simple distributional changes (the attraction hypothesis) versus total abundance rise (the production hypothesis). Here we develop a modelling framework based on simple, inexpensive fisheries data to quantify the impact of ARs, disentangling attraction from production by assessing the rise in regional K. The rationale is that if attraction to ARs from the wider region was the main driver of increased abundance in the ARs then regional K would have remained constant before, during and after deployment of the ARs. Therefore an increase in regional K disproves the hypothesis of attraction. The study case is the fishery for the two-banded seabream Diplodus vulgaris in southern Portugal. Monthly time series of 27 years of landings, 20 years of fishing effort, were available from three small-scale fleets: one was the artisanal fleet operating on the ARs and the other two were semi-industrial fleets operating on the wider continental shelf. The model that we developed and applied incorporated the data from all fleets so it evaluated the change in regional K. We show that regional K for D. vulgaris increased by 35% after final deployment of the ARs and it did so in linear fashion during four years. From a fisheries perspective the result was more nuanced because although the deployment succeeded in raising regional K, stock biomass and thereby enhancing the artisanal fishery, it also led to a substantial rise in total fishing mortality and exploitation rate because the semi-industrial fleets operating offshore increased their harvest rate nearly 3-fold. Our modelling framework has wide applicability in other regions due to the elementary nature of the necessary fishing monitoring data.Fundacao para a Ciencia e TecnologiaPortuguese Foundation for Science and Technology [SFRH/BPD/108949/2015]FCT -Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [DID/Multi/04326/2013