Research

17 pages, 4388 KiB

Open AccessArticle

Sharks Do Not Always Grow Slowly: Tagging Data Reveal a Different Pattern of Growth, Longevity and Maturity for Threatened Smooth-Hounds in the Central Mediterranean Sea

by Gabriele Boscolo Palo, Manfredi Di Lorenzo, Salvatore Gancitano, Sergio Ragonese, Carlotta Mazzoldi and Francesco Colloca

J. Mar. Sci. Eng. 2022, 10(11), 1647; https://doi.org/10.3390/jmse10111647 - 03 Nov 2022

Cited by 3 | Viewed by 1772

Abstract

Elasmobranchs are among the marine species more threatened by overfishing. Their conservation is often impaired by the lack of knowledge of species’ life history traits. We filled knowledge gaps on age and growth of two threatened smooth-hound sharks (Mustelus mustelus, Mm [...] Read more.

Elasmobranchs are among the marine species more threatened by overfishing. Their conservation is often impaired by the lack of knowledge of species’ life history traits. We filled knowledge gaps on age and growth of two threatened smooth-hound sharks (Mustelus mustelus, Mm; Mustelus punctulatus, Mp) in the central Mediterranean Sea, combining standard vertebrae analysis with growth increment data from a tagging survey. Our data revealed that the two species grow at a faster rate than previously estimated using vertebrae reading only. The maximum age/size found was higher for Mm (16 years, 170 cm TL) than Mp (8 years, 120 cm TL), the first species attaining larger size-at-age than the second one. Mp reaches maturity at earlier ages (A₅₀ 3 years for both females and males) than Mm (A₅₀ females: 4 years; males: 3 years). The use of the tag-recapture method to validate the growth rate, firstly derived by sectioned vertebrae readings, highlighted the presence of false check marks. The new estimates of growth and longevity have important implications for the assessment of natural mortality, productivity, and stock resilience to fishing pressure which, combined with the high site fidelity highlighted by tagging data, may have crucial implications for the conservation of these two threatened sharks in the Mediterranean Sea. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

14 pages, 2434 KiB

Open AccessArticle

Morphometric Analyses of Phenotypic Plasticity in Habitat Use in Two Caspian Sea Mullets

by Shima Bakhshalizadeh, Keyvan Abbasi, Adeleh Rostamzadeh Liafuie, Ali Bani, Anu Pavithran and Francesco Tiralongo

J. Mar. Sci. Eng. 2022, 10(10), 1398; https://doi.org/10.3390/jmse10101398 - 30 Sep 2022

Cited by 4 | Viewed by 1305

Abstract

To understand the functional meaning of morphological traits in the exploitation of natural resources, it is necessary to develop a quantitative, meaningful scheme for understanding ecophenotypes; this will facilitate management and conservation, which are the most pressing challenges in vulnerable aquatic environments. In [...] Read more.

To understand the functional meaning of morphological traits in the exploitation of natural resources, it is necessary to develop a quantitative, meaningful scheme for understanding ecophenotypes; this will facilitate management and conservation, which are the most pressing challenges in vulnerable aquatic environments. In this context, the management of cryptic and very similar species is more challenging, because of the difficulty of distinguishing them and determining their frequency in sympatry, even though they do not necessarily have the same ecologies. As such, in order to understand how morphological similarities are associated with their ecology, thirteen morphometric characteristics related to body landmark-based geometric morphometries, sagittal otolith morphology, and shape were examined in mature Chelon auratus and Chelon saliens, which were collected from the coastal waters of the southwest Caspian Sea between October 2020 and April 2021. Univariate and multivariate analysis of variance were conducted to evaluate the potential morphological differences between the species. The analyses highlight the morphological differences between C. auratus and C. saliens, and identify potentially helpful traits for using body and otolith shape for the interspecific distinction of these very similar species of Caspian mullet, which can reflect functional similarity and are an important component of community ecology. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

10 pages, 2347 KiB

Open AccessArticle

First Estimates of Age and Growth of the Lusitanian Cownose Ray (Rhinoptera marginata) from the Mediterranean Sea

by Nuri Başusta, Asiye Başusta, Erdoğan Çiçek, Angela M. Cicia and James A. Sulikowski

J. Mar. Sci. Eng. 2022, 10(5), 685; https://doi.org/10.3390/jmse10050685 - 18 May 2022

Cited by 1 | Viewed by 2145

Abstract

Within the eastern Mediterranean, increased fishing pressure coupled with a lack of basic biological information is threatening the sustainability of the rare Lusitanian cownose ray (Rhinoptera marginata). To provide baseline life-history data for this species, age estimates were obtained from vertebral [...] Read more.

Within the eastern Mediterranean, increased fishing pressure coupled with a lack of basic biological information is threatening the sustainability of the rare Lusitanian cownose ray (Rhinoptera marginata). To provide baseline life-history data for this species, age estimates were obtained from vertebral band counts of 224 rays (size range: 210–998 mm disc width and 140 to 13,600 g weight) collected from Iskenderun Bay. Females ranged in size from 210 to 998 mm disc width and 238 to 13,600 g weight, while males ranged from 130 to 866 mm disc width and 140 to 8250 g weight. The index of average percent error (2.8%) and age-bias plot suggest that the aging method used represents a precise and non-biased approach. Marginal increment analysis indicated that a single opaque band is deposited annually between August and September. The oldest ages obtained for R. marginata were 9 years for males and 19 years for females, which corresponded to total lengths of 866 and 998 mm disc width, respectively. For males, limited samples prevented the accurate calculation of growth rates; however, for combined sexes, observed and disc width-at-age data resulted in the following von Bertalanffy growth parameters: DW_∞ = 1102.16 mm, k = 0.148 and t₀ = −0.2167. Although additional samples are necessary to determine growth rates in males, the results of the present study indicate that R. marginata females exhibit life history characteristics similar to other Rhinoptera species. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

22 pages, 3111 KiB

Open AccessArticle

Microplastics in the Deep: Comparing Dietary and Plastic Ingestion Data between Two Mediterranean Bathyal Opportunistic Feeder Species, Galeus melastomus, Rafinesque, 1810 and Coelorinchus caelorhincus (Risso, 1810), through Stomach Content Analysis

by Umberto Scacco, Emanuele Mancini, Federica Marcucci and Francesco Tiralongo

J. Mar. Sci. Eng. 2022, 10(5), 624; https://doi.org/10.3390/jmse10050624 - 02 May 2022

Cited by 12 | Viewed by 2897

Abstract

Marine plastic pollution is currently an issue of mounting concern around the world. Stomach content of marine fish has been increasingly used as a valid proxy for detecting the presence of such a pollutant in marine biota, both for coastal and deep-water environments. [...] Read more.

Marine plastic pollution is currently an issue of mounting concern around the world. Stomach content of marine fish has been increasingly used as a valid proxy for detecting the presence of such a pollutant in marine biota, both for coastal and deep-water environments. Although ingestion of microplastics has been reported in an increasing number of species, the patterns of ingestion still remain unclear, depending closely on the interaction between the species and types of microplastics involved. In this context, we analysed and compared the stomach contents of two bathyal dwelling opportunistic feeder species namely Galeus melastomus and Coelorinchus caelorhincus. In particular, we analysed microplastic items according to their dimension, morphology and colour, and diet’s variation with size obtained through prey identification. Both species showed a higher frequency of occurrence of the blue filament-like middle-sized microplastics (1.01–4.75 mm) compared with the other categories, although this pattern was much more marked in C. caelorhincus than in G. melastomus. The latter conversely showed a larger array of ingested plastic items in terms of shape and colour. Matching plastic ingestion with dietary data suggested potential predator confusion occurring in C. caelorhincus through active mis-selection of a defined type of microplastic instead of some particular family of polychaetes, which resemble in shape, size, and color to that type. Otherwise, G. melastomus appeared more prone to a random ingestion of a larger array of microplastic items because of a more generalistic and less selective feeding strategy. Although further validation is needed, stomach contents of the two species showed evidence strong enough to be considered as potential bioindicator species of microplastic pollution, as required by the Marine Strategy Framework Directive for monitoring this pollutant in the marine environment. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

9 pages, 2348 KiB

Open AccessArticle

Estimation of Stock Status Using the LBB and CMSY Methods for the Indian Salmon Leptomelanosoma indicum (Shaw, 1804) in the Bay of Bengal, Bangladesh

by Md. Abdullah Al-Mamun, Md. Mostafa Shamsuzzaman, Petra Schneider, Mohammad Mojibul Hoque Mozumder and Qun Liu

J. Mar. Sci. Eng. 2022, 10(3), 366; https://doi.org/10.3390/jmse10030366 - 04 Mar 2022

Cited by 6 | Viewed by 2727

Abstract

As one of the largest and most commercially valuable finfish species, Leptomelanosomaindicum (Indian salmon) significantly contributes to Bangladesh’s marine catches. The length-based Bayesian biomass (LBB) method and catch-based Monte Carlo method (CMSY) are among the most recent and powerful methods for predicting [...] Read more.

As one of the largest and most commercially valuable finfish species, Leptomelanosomaindicum (Indian salmon) significantly contributes to Bangladesh’s marine catches. The length-based Bayesian biomass (LBB) method and catch-based Monte Carlo method (CMSY) are among the most recent and powerful methods for predicting the state of fisheries resources from data-limited fisheries. CMSY requires catch and resilience data, as well as quantitative stock status information. For LBB, only length–frequency (LF) data are required. The stock status of L. indicum was estimated using these two independent methods, utilizing twenty-one years of catch–effort and length–frequency data (978 individuals) from commercial fisheries on the Bangladesh coast. Here, a BSM (Bayesian state-space implementation of the Schaefer surplus production model) was also employed. The current study’s findings showed that the B/B₀ ratio of currently exploited biomass to unexploited biomass (0.1) was smaller than B_MSY/B₀ (0.36) and B/B_MSY = 0.28 was smaller than the reference value of 1.0, indicating the grossly overfished and depleted condition of the stock. Similar trends in the results were found for B/B_MSY = 0.11 (<1.0) from CMSY. In addition, the exploitation rate (F/F_MSY = 5.66), biomass (B < B_MSY), and fishing status (F > F_MSY) further justify the severely overfished conditions of L. indicum stock in the study area. Furthermore, the L_{c_opt} (optimal length at first capture) was higher than the L_c (length at first capture), indicating that this species is being overfished, and that mesh sizes should be increased for better management. This study provides information on biological reference points (BRPs), and confirms the severely overfished status of L. indicum in the coastal waters of Bangladesh. More specific and prompt management measures are required to recover and sustainably manage this valuable species, and protect the fish stock from commercial extinction. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

9 pages, 1312 KiB

Open AccessArticle

Meridionalization as a Possible Resource for Fisheries: The Case Study of Caranx rhonchus Geoffroy Saint-Hilaire, 1817, in Southern Italian Waters

by Salvatore Coco, Alessandra Roncarati, Francesco Tiralongo and Alberto Felici

J. Mar. Sci. Eng. 2022, 10(2), 274; https://doi.org/10.3390/jmse10020274 - 16 Feb 2022

Cited by 5 | Viewed by 2992

Abstract

Climate change affects the shift range distribution of species, especially among mobile species, and this phenomenon can alter ecosystems and impacts human activities. Fishing is an anthropic activity that undergoes the effect not only of the introduction and increase of non-native species but [...] Read more.

Climate change affects the shift range distribution of species, especially among mobile species, and this phenomenon can alter ecosystems and impacts human activities. Fishing is an anthropic activity that undergoes the effect not only of the introduction and increase of non-native species but also of native thermophilic ones. Some of these species can become a commercially exploitable resource. However, this information is often obscured by the negative effects these species can cause to the environment. We investigated how the thermophilic species Caranx rhonchus, neglected in Italy, could become a relevant resource. We studied the nutritional profile and the presence of heavy metal contamination and compared these traits with those of a similar common Mediterranean species, namely Trachurus trachurus. The proximate composition was determined following the AOAC procedure, while the fatty acid profile was determined by GC/MS, and the mineral component was obtained by mass spectrometer (ICP-MS). Caranx rhonchus is a nutritionally good species, although it is little consumed and exploited. Increasing the market supply with new commercially exploitable emerging species would benefit local communities and the environment. Therefore, it is necessary to investigate how a shift of the range caused by climate change can provide benefits within the human dimension. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

16 pages, 17663 KiB

Open AccessFeature PaperArticle

Strengthening Angel Shark Conservation in the Northeastern Mediterranean Sea

by Ioannis Giovos, Dimitra Katsada, Roxani Naasan Aga Spyridopoulou, Dimitrios Poursanidis, Aggeliki Doxa, Stelios Katsanevakis, Periklis Kleitou, Vasiliki Oikonomou, Vasileios Minasidis, Ayaka A. Ozturk, Dimitra Petza, Maria Sini, Cahide Cigdem Yigin, Eva K. M. Meyers, Joanna Barker, David Jiménez-Alvarado and Ali R. Hood

J. Mar. Sci. Eng. 2022, 10(2), 269; https://doi.org/10.3390/jmse10020269 - 15 Feb 2022

Cited by 5 | Viewed by 4985

Abstract

Angel sharks are among the most threatened species of sharks globally. Twenty-two species have been identified globally so far, with three species being present in the Mediterranean Sea: Squatina aculeata, Squatina oculata, and Squatina squatina. The Mediterranean populations of all [...] Read more.

Angel sharks are among the most threatened species of sharks globally. Twenty-two species have been identified globally so far, with three species being present in the Mediterranean Sea: Squatina aculeata, Squatina oculata, and Squatina squatina. The Mediterranean populations of all three species have been assessed as Critically Endangered by the IUCN Red List of Threatened Species due to the steep decline of their populations as a result of their historical and current overexploitation by demersal fisheries. Therefore, currently there is an ongoing increasing effort for advancing the conservation of the species in the basin. Recently, in the context of the Regional Action Plan for Mediterranean Angel Sharks, the Aegean Sea and Crete have been identified as critical areas for all three species. This study provides the first predictive distribution map of the three angel shark species in the basin, while critical areas for the conservation of the species were identified through a systematic spatial conservation planning analysis. Our analysis revealed low overlapping between the existing MPA network and critical areas for the distribution of the species primarily in Greece and then Turkey, while 20% of the critical areas for the distribution of the species overlaps with Fisheries Restricted Areas of the region. This highlights the need for creating MPAs focusing on shark conservation within the Mediterranean that are currently completely absent. In addition, we provide policy recommendations that can secure better protection of angel sharks through the enforcement of the current legislations and the engagement of all relevant stakeholders. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

12 pages, 2356 KiB

Open AccessArticle

Fisheries Reference Point and Stock Status of Croaker Fishery (Sciaenidae) Exploited from the Bay of Bengal, Bangladesh

by Partho Protim Barman, Md. Mostafa Shamsuzzaman, Petra Schneider, Mohammad Mojibul Hoque Mozumder and Qun Liu

J. Mar. Sci. Eng. 2022, 10(1), 63; https://doi.org/10.3390/jmse10010063 - 05 Jan 2022

Cited by 10 | Viewed by 2269

Abstract

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte [...] Read more.

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte Carlo method (CMSY) and the Bayesian state-space Schaefer surplus production model (BSM) method. This research applies a Stock–Production Model Incorporating Covariates (ASPIC) software package to run the Schaefer and Fox model. The maximum sustainable yield (MSY) produced by all models ranged from 33,900 to 35,900 metric tons (mt), which is very close to last year’s catch (33,768 mt in 2016). The estimated B > B_MSY and F < F_MSY indicated the safe biomass and fishing status. The calculated F/F_MSY was 0.89, 0.87, and 0.81, and B/B_MSY was 1.05, 1.07, and 1.14 for Fox, Schaefer, and BSM, respectively, indicating the fully exploited status of croaker stock in the BoB, Bangladesh. The representation of the Kobe phase plot suggested that the exploitation of croaker stock started from the yellow (unsustainable) quadrant in 2001 and gradually moved to the green (sustainable) quadrant in 2016 because of the reduction in fishing efforts and safe fishing pressure after 2012. Thus, this research suggests that the current fishing pressure needs to be maintained so that the yearly catch does not exceed the MSY limit of croaker. Additionally, specific management measures should implement to guarantee croaker and other fisheries from the BoB. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

17 pages, 3607 KiB

Open AccessArticle

Biological and Ecological Aspects of the Blackmouth Catshark (Galeus melastomus Rafinesque, 1810) in the Southern Tyrrhenian Sea

by Claudio D’Iglio, Marco Albano, Francesco Tiralongo, Sergio Famulari, Paola Rinelli, Serena Savoca, Nunziacarla Spanò and Gioele Capillo

J. Mar. Sci. Eng. 2021, 9(9), 967; https://doi.org/10.3390/jmse9090967 - 06 Sep 2021

Cited by 26 | Viewed by 4574

Abstract

Data on the biology and ecology of Galeus melastomus are old/absent for the Southern Tyrrhenian Sea, despite there being numerous studies in the wider area. A total of 127 specimens of G. melastomus from the southern Tyrrhenian Sea, collected in 2018–2019 using trawling [...] Read more.

Data on the biology and ecology of Galeus melastomus are old/absent for the Southern Tyrrhenian Sea, despite there being numerous studies in the wider area. A total of 127 specimens of G. melastomus from the southern Tyrrhenian Sea, collected in 2018–2019 using trawling nets, were analyzed to investigate size at sexual maturity, sex ratio, length–weight relationships, and feeding habits. To our best knowledge, this is the first time in which all these features were investigated in the Southern Tyrrhenian Sea for G. melastomus. The stomach content analysis showed that G. melastomus had intermediate feeding habits, preying on a great variety of species, especially Cephalopoda, Osteichthyes, and Crustacea. The Levin’s index value (Bi) was 0.53. Sex ratio was 0.92:1, with females slightly more abundant and bigger than males. The results also showed a decrease (33.7 cm for females, 31.1 cm for males) in length at 50% maturity (L₅₀). This could be a result of anthropogenic stressors, such as overfishing and/or and environmental changes, which can induce physiological responses in several species. Our results highlighted the differences related to sexual maturity, growth, and feeding habits of the blackmouth catshark in the studied area, providing reference data to allow comparison with future studies on this species adaptations to this and other deep-sea areas in the Mediterranean Sea. Full article

(This article belongs to the Special Issue Coastal Fish Research II)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Coastal Fish Research II

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI