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The article informs on mantelline in the Canary Islands. It mentions the mantelline aggregates in different areas of the islands, forming a carpet on the seabed, in many cases making it impossible to see the sand clearly, and camouflage is their main weapon, since they feed by ambushing their prey. It also mentions about its ecology.

The article focuses on spearfishing and its impact on fishery resources in the Canary Islands. It notes that modern underwater fishing, wearing mask diving and rifle was developed in the Mediterranean, in the decade of 1930. It adds that the realization of the type of fishing, unlike the rest of recreational fishing modalities, demand of great physical capacity by the fisherman, mainly because of the need to dive prolonged apnea and long periods of exposure the water.

In this study, we used a historical collection of photographs taken by recreational fishers from 1940 to 2014, at the island of Gran Canaria, to show both a significant decrease in the mean total length of Epinephelus marginatus and a concurrent change in the composition of captures. Before 1980, the mean total length of fish caught and photographed was c. 100 cm, while after 2009 this was typically < 40 cm. Before 1980, the predominant captured species was E. marginatus (an apex predator), but currently the majority of catches are of omnivorous species, in particular the parrotfish, Sparisoma cretense and seabreams Diplodus spp. Overall, integration of these results indicates a qualitative and quantitative variation in captures of recreational fishers, probably as a sign of change in ecological balances and the overfished status of many target species. [ABSTRACT FROM AUTHOR]

The article reports on the acoustic monitoring of the behavior of angel in the Canary Islands. It notes that the conservation of the angel in the Canary Islands has managed to take a new qualitative leap after the completion of the project. It adds that the Canary Islands are today the last stronghold of stable populations of this species, as well as its inclusion in the Spanish Species Catalog.

Analysis of 322 cuttlebones of Sepia bertheloti caught in the waters of the Northwest Africa showed significant differences in growth between males and females. Morphometric analysis revealed a relatively different cuttlebone growth pattern between sexes, with males presenting faster growth in length to reach larger sizes and females displaying greater growth in width. This difference in cuttlebone growth is related to female gonadal development and the subsequent increase of the paleal cavity, providing more support and space to accommodate a higher number of oocytes. [ABSTRACT FROM AUTHOR]

The article reports that the Atlantic Society of Oceanographers (SAO), in collaboration with the University of Las Palmas de Gran Canaria and the Canary Islands Government, organized the Oceans Forum 2019. It notes that the Atlantic Society of Oceanographers (SAO) has more than 8 years developing activities in favor of knowledge transfer from centers of research to society and administrations public.

In this study, we explored the feasibility of using the beaks of the African cuttlefish Sepia bertheloti for age estimation and growth analysis. The rostrum sagittal section (RSS) of the lower beak was the most suitable region in the species. It was applied in samples caught off Morocco and Guinea-Bissau between June 2018 and January 2020. A maximum life expectancy of around 14 months was observed (specifically 419 days for cuttlefishes from Morocco and 433 from Guinea-Bissau). The males presented greater longevity, as the maximum age of the females was between 9 and 11 months. Sepia bertheloti showed a negative allometric growth; however, the exponential model better describes each population growth. By sexes, the males of both locations followed an asymptotic growth model while the females exhibited a non-asymptotic growth. The growth rates were different between locations, with the highest values in Guinea-Bissau. The males, in turn, grew faster for both study locations. In Guinea-Bissau, these growth differences were influenced by the hatching season since individuals born between autumn and winter were the fastest-growing. Samples from Morocco did not show growth differences between the hatching season and other seasons. These results indicate that the RSS of lower beaks are suitable for estimating the age, growth pattern, and population structure of Sepia bertheloti. [ABSTRACT FROM AUTHOR]

Simple Summary: We investigated the status and population structure of Percnon gibbesi in three areas of the island of Gran Canaria (Canary Islands, Central-East Atlantic) between July 2020 and December 2021. A total of 999 individuals were captured. Monthly sampling allowed us to establish the reproductive season according to the presence of ovigerous females. The methodology and number of individuals analysed were suitable for establishing the length–weight relationships and the life history parameters via modal progression analysis. The analysis of the catches per unit effort (CPUE) revealed the abundance of Percnon gibbesi in the three areas and seems to not conform with the catch quotas established in the Canary Islands Fisheries Law. Percnon gibbesi is a native crab species characteristic of intertidal and subtidal zones of the Atlantic coast of the European Macaronesian archipelagos (Azores, Madeira, and Canary Islands), and probably also in the neighbouring rocky coasts of northwest Africa. P. gibbesi is considered an invasive alien species in almost all of the Mediterranean, with expanding populations from Spain to Turkey, including Libya; However, its biology and ecology are highly unknown, despite all its range of distribution. In the intertidal zones of Gran Canaria Island, this crab, in the intertidal zones of Gran Canaria Island, shows a carapace length range between 4.1 and 22.7 mm (4.1–22.7 in males and 5.7–22.3 in females), where females showed higher weights and lengths than males on average; However, males predominated in all samples, with a sex ratio of 1:0.57. The L∞ for this crab was estimated to be 27 ± 3 mm (23 ± 4 mm for females and 25 ± 4 mm for males). The growth coefficient (K) was 0.24 year−1, the total mortality (Z) was Z = 1.71 year−1, and the natural mortality (M) was 0.47 year−1. Although females grow faster than males, males are more abundant in the larger length classes. Although the presence of ovigerous females indicated that reproduction takes place twice a year, from March to April and from August to September, the number of cohorts detected by the modal progression analysis showed that reproduction takes place all year. [ABSTRACT FROM AUTHOR]

This is the first study addressing validation of the early growth stages (including the first increment) in the beaks of juvenile cuttlefishes. The age validation in juveniles of Sepia officinalis was performed by comparison of the number of increments observed in the rostrum surface of lower jaws with their true age. A total of 159 individuals were reared at 18 ºC and 21 ºC, with ages up to 31 days from hatching. The number of growth increments in the beak was counted and contrasted with the days of life after hatching, validating the hypothesis of one increment of growth corresponding to one day of life. The mean coefficient of variation between readings (measuring precision) was 2.95 ± 5.98%. The growth of the reading area (rostrum surface) and the periodicity of increment deposition showed no difference between the two culture temperatures and therefore daily deposition was confirmed at these temperatures. [ABSTRACT FROM AUTHOR]

The article presents information about artificial reefs in the Canary Islands from 1983 to 2021. These reefs are used to improve fishing and protect areas of ecological and fishing interest. However, if not properly managed, they can promote overexploitation of aggregated species. In the Canary Islands, there are six areas of artificial reefs located in La Palma, Gran Canaria, Lanzarote, and Fuerteventura. These reefs are composed of attraction-aggregation modules and some structures to prevent trawling. It is suggested to implement strict regulation of fishing fleet access to the reefs and raise awareness among fishermen about their importance. [Extracted from the article]

Batoids, distributed from shallow to abyssal depths, are considerably vulnerable to anthropogenic threats. Data deficiencies on the distribution patterns of batoids, however, challenge their effective management and conservation. In this study, we took advantage of the particular geological and geomorphological configuration of the Canary Islands, across an east‐to‐west gradient in the eastern Atlantic Ocean, to assess whether patterns in the occurrence and abundance of batoids varied between groups of islands (western, central, and eastern). Data were collected from shallow (<40 m, via underwater visual counts and by a local community science program) and deep waters (60–700 m, via ROV deployments). Eleven species of batoids, assessed by the IUCN Red List of Threatened Species, were registered, including three "Critically Endangered" (Aetomylaeus bovinus, Dipturus batis, and Myliobatis aquila), three "Endangered" (Gymnura altavela, Mobula mobular, and Rostroraja alba), two "Vulnerable" (Dasyatis pastinaca and Raja maderenseis), and two "Data Deficient" (Taeniurops grabata and Torpedo marmorata). Also, a "Least Concern" species (Bathytoshia lata) was observed. Overall, batoids were ~1 to 2 orders of magnitude more abundant in the central and eastern islands, relative to the western islands. This pattern was consistent among the three sources of data and for both shallow and deep waters. This study, therefore, shows differences in the abundance of batoids across an oceanic archipelago, likely related to varying insular shelf area, availability of habitats, and proximity to the nearby continental (African) mass. Large variation in population abundances among islands suggests that "whole" archipelago management strategies are unlikely to provide adequate conservation. Instead, management plans should be adjusted individually per island and complemented with focused research to fill data gaps on the spatial use and movements of these iconic species. [ABSTRACT FROM AUTHOR]

Abralia veranyi and Abraliopsis morisii were the most abundant cephalopods caught during epipelagic and mesopelagic surveys off the Canary Islands and accounted for 26% and 35% of the cephalopod catch, respectively. Diel vertical migration patterns were observed in both species. At night, A. veranyi was recorded at depths as shallow as 38–90 m, whereas Abraliopsis morisii occurred at depths of 98–219 m. As individuals grow in mantle length, their diet changes substantially. Abraliopsis morisii showed ontogenetic shifts at 22.9 mm and 35.3 mm dorsal mantle length (DML), while A. veranyi showed ontogenetic shifts at 20.5 mm and 30.9 mm DML. Prior to the first ontogenic shift, both species fed mainly on copepods and mysids. After this shift they fed on larger prey, such as decapods and fish; the diets of larger individuals also contained cephalopods. [ABSTRACT FROM AUTHOR]

The African cuttlefish, Sepia bertheloti , is a commercially exploited cephalopod in two productive system areas off West Africa. However, there is a lack of information on its feeding ecology, making it difficult to describe its ecological role (Morocco and Guinea-Bissau). In the present study, we analyse the gastric contents of 1.114 individuals, collected between July 2018 and January 2020 using the traditional analysis of stomach contents. A total of 65 and 49 prey items were identified as part of the diet of Moroccan and Guinean African cuttlefish, respectively. The sample size was evaluated using species cumulative curves and the methods used to describe the diet were the frequency of occurrence, number, and weight. Our results suggest that S. bertheloti does not present differences in diet between sexes or areas, although significant differences were observed in terms of prey abundance, richness, and diversity of species. According to the taxonomic groups, crustaceans were the most abundant prey taxa, followed by fish and cephalopods. Amphipods (Gammarus sp.) were the prey that showed the greater importance of occurrence in the diet at both study areas, showing a strictly benthic feeding behaviour. Niche breadth was evaluated using Levin's index, indicating that S. bertheloti is an omnivorous species (Trophic level ∼3.6) with a heterogeneous diet and without a marked generalist or specialist feeding strategy. • Cuttlefish from North and West-Central Africa showed a similar diet. • Gammarus spp. Was the most frequently identified prey. • Prey abundance were 3.19 and 1.43 for Morocco and Guinea-Bissau. • Sepia bertheloti is an omnivorous species with a Trophic Level∼3.6. • Sepia bertheloti is an euryphagic feeder. [ABSTRACT FROM AUTHOR]

In this paper we consider what may happen to the marine ecosystem of Gran Canaria Island within the 2030 horizon, if fishing strategies different from those currently in place were implemented and we evaluate the effect of, for example, reduction of recreational–artisanal fishing, limitation of catches (e.g. total allowable catches, TAC), or spatial distribution of fishing sectors. From all scenarios tested, only those that significantly reduce the high effort of the recreational fishing would allow the recovery of the most exploited stocks in the marine ecosystem in the short and medium‐term. Moreover, the best management strategy, in contribution to abundance, was obtained with a scenario that has a spatial partition of exploitation rights between artisanal and recreational fishermen and includes no‐fishing zones (NTZ). This work is a first attempt to use spatial and temporal models to assess the effectiveness of alternative fishery policies in the Canary Islands. [ABSTRACT FROM AUTHOR]