Conservation and Management of Marine Ecosystems

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Journal of Marine Science and Engineering jmse	2.7	4.4	2013	16.9 Days	CHF 2600
Oceans oceans	1.5	3.1	2020	32.2 Days	CHF 1600
Remote Sensing remotesensing	4.2	8.3	2009	24.7 Days	CHF 2700
Sustainability sustainability	3.3	6.8	2009	20 Days	CHF 2400
Water water	3.0	5.8	2009	16.5 Days	CHF 2600

14 pages, 1754 KiB

Open AccessArticle

Ecosystem Structure and Function in the Sea Area of Zhongjieshan Islands Based on Ecopath Model

by Yao Qu, Zhongming Wang, Yongdong Zhou, Jun Liang, Kaida Xu, Yazhou Zhang, Zhenhua Li, Qian Dai, Qiuhong Zhang and Yongsheng Jiang

J. Mar. Sci. Eng. 2024, 12(11), 2086; https://doi.org/10.3390/jmse12112086 - 18 Nov 2024

Abstract

Based on the field survey and reference data of the sea area of the Zhongjieshan Islands from 2021 to 2022, the Ecopath model was used to analyze the energy flow structure of the marine ecosystem of the sea area of the Zhongjieshan Islands; [...] Read more.

Based on the field survey and reference data of the sea area of the Zhongjieshan Islands from 2021 to 2022, the Ecopath model was used to analyze the energy flow structure of the marine ecosystem of the sea area of the Zhongjieshan Islands; the energy structure of the marine ecosystem was divided into 21 functional groups, and its nutrient structure, energy flow, and total system characteristics were analyzed. The results show that the credibility of the model is 0.414, which is at a medium level. The trophic level of each functional group of the ecosystem in the sea area of Zhongjieshan Islands was 1–3.48, the energy flow structure of the system was mainly concentrated in the first five grades, and the trophic level was relatively simple, with the average energy transfer efficiency of the system being 8.11%, the energy flow range being 2.81–13.04%, the energy transfer efficiency of the primary producers of the system being 7.25%, and the energy conversion efficiency of the system debris being 9.12%. The total system throughput was 2125.96 t·km⁻²; The analysis of the overall characteristics of the ecosystem showed that the system connectance index and the system omnivory index were 0.45 and 0.24, respectively, while the Finn’s cycling index was 8.24, the Finn’s mean path length of the system was 2.72, and the total primary production/total respiration was 1.71. In this study, the marine ecosystem model of the sea area of the Zhongjieshan Islands was studied to understand the trophic structure and ecosystem status of the sea area, which is conducive to the sustainable utilization and scientific management of fishery resources in the sea area. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

16 pages, 10303 KiB

Open AccessArticle

Deep Learning-Based Automatic Estimation of Live Coral Cover from Underwater Video for Coral Reef Health Monitoring

by Zechen Li, Shuqi Zhao, Yuxian Lu, Cheng Song, Rongyong Huang and Kefu Yu

J. Mar. Sci. Eng. 2024, 12(11), 1980; https://doi.org/10.3390/jmse12111980 - 2 Nov 2024

Viewed by 624

Abstract

Coral reefs are vital to marine biodiversity but are increasingly threatened by global climate change and human activities, leading to significant declines in live coral cover (LCC). Monitoring LCC is crucial for assessing the health of coral reef ecosystems and understanding their degradation [...] Read more.

Coral reefs are vital to marine biodiversity but are increasingly threatened by global climate change and human activities, leading to significant declines in live coral cover (LCC). Monitoring LCC is crucial for assessing the health of coral reef ecosystems and understanding their degradation and recovery. Traditional methods for estimating LCC, such as the manual interpretation of underwater survey videos, are labor-intensive and time-consuming, limiting their scalability for large-scale ecological monitoring. To overcome these challenges, this study introduces an innovative deep learning-based approach that utilizes semantic segmentation to automatically interpret LCC from underwater videos. That is, we enhanced PSPNet for live coral segmentation by incorporating channel and spatial attention mechanisms, along with pixel shuffle modules. Experimental results demonstrated that the proposed model achieved a mean Intersection over Union (mIoU) of 89.51% and a mean Pixel Accuracy (mPA) of 94.47%, showcasing superior accuracy in estimating LCC compared to traditional methods. Moreover, comparisons indicated that the proposed model aligns more closely with manual interpretations than other models, with an mean absolute error of 4.17%, compared to 5.89% for the original PSPNet, 6.03% for Deeplab v3+, 7.12% for U-Net, and 6.45% for HRNet, suggesting higher precision in LCC estimation. By automating the estimation of LCC, this deep learning-based approach can greatly enhance efficiency, thereby contributing significantly to global conservation efforts by enabling more scalable and efficient monitoring and management of coral reef ecosystems. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

15 pages, 1835 KiB

Open AccessArticle

Inventory of Shallow-Water Fouling Invertebrates of Long Island, New York

by Ezra Roesch, Jack H. Rosencrans, Kent A. Hatch and Robert W. Thacker

Oceans 2024, 5(4), 825-839; https://doi.org/10.3390/oceans5040047 - 1 Nov 2024

Viewed by 722

Abstract

Invasive marine invertebrates are increasingly recognized as a potential disturbance to coastal ecosystems. We sought to better document the taxonomic composition of subtidal communities around Long Island to obtain a baseline that can be used to monitor current and future invasions of non-indigenous [...] Read more.

Invasive marine invertebrates are increasingly recognized as a potential disturbance to coastal ecosystems. We sought to better document the taxonomic composition of subtidal communities around Long Island to obtain a baseline that can be used to monitor current and future invasions of non-indigenous species. We placed settlement blocks at 18 sites along the coast of Long Island, New York, for three months. After recovering blocks at 12 sites, we analyzed the taxonomic composition of fouling communities on the blocks. We observed 64 invertebrate and 3 algal taxa, with large variation in taxon richness among sites. Multivariate analyses revealed that although taxon composition was significantly dissimilar between north and south shores, variation in dissimilarity did not differ significantly between shores. The high variability in taxon composition observed among sites indicates that additional research is needed to expand our knowledge of invertebrate diversity in the waters surrounding Long Island. Adding more sites and replicate blocks within sites could improve future sampling designs. This research will benefit continuing efforts to monitor, manage, and prevent the establishment of marine invasive species. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

Figure 1
Sites where settlement blocks were placed. Closed circles indicate sites where no settlement plates were collected either because the plates or the entire block were lost. Open circles represent sites where at least one settlement plate was collected. Site names are as follows: A = Kings Point; B = Silver Point; C = East Island; D = Point Lookout; E = Lloyd Harbor; F = Sore Thumb, Gilgo State Park; G = Crane Neck; H = Smith Point; I = Wildwood; J = Cupsogue Beach; K = Reeves Beach; L = Shinnecock Inlet; M = Bailie Beach; N = W. Scott Cameron Beach; O = Horton Point; P = Hog Creek Point; Q = Orient Point; R = Montauk Point. GPS coordinates for each location are provided in <a href="#oceans-05-00047-t001" class="html-table">Table 1</a>. Full article ">Figure 2
Diagram of cement block and Petri dish settlement plates. Blocks were placed at subtidal depths such that the settlement plates remained submerged throughout the tidal cycle. Full article ">Figure 3
The median number of taxa found per settlement plate at each location. Bold lines indicate the median values, while boxes delimit the second and third quartiles, and lines indicate the maximum and minimum values. Locations with a single bar indicate that only one plate could be analyzed at that location. Full article ">Figure 4
The median number of taxa found per site on north and south shores of Long Island. Bold lines indicate the median values among sites, while boxes delimit the second and third quartiles, and lines indicate the maximum and minimum values. Full article ">Figure 5
Rarefaction curves describing the accumulation of unique taxa across sites on the north (dark gray) and south (light gray) shores of Long Island, as well as on both shores combined (black). Full article ">Figure 6
Non-metric multidimensional scaling plot comparing each settlement plate’s taxonomic dissimilarity as measured by the Jaccard index (stress = 0.198, non-metric fit R2 = 0.97). Open circles represent sites on the north shore of Long Island, while filled circles represent sites on the south shore. Plate angle is not indicated since it was not found to be a significant factor (p = 0.804). Full article ">Figure 7
Number of cryptogenic, indigenous, non-indigenous, and unresolved taxa at each location. The relative abundances of these categories were not significantly different among locations (chi-square = 19.12, df = 33, p = 0.974). Full article ">

13 pages, 7781 KiB

Open AccessArticle

Operational Mapping of Submarine Groundwater Discharge into Coral Reefs: Application to West Hawai‘i Island

by Gregory P. Asner, Nicholas R. Vaughn and Joseph Heckler

Oceans 2024, 5(3), 547-559; https://doi.org/10.3390/oceans5030031 - 5 Aug 2024

Viewed by 1282

Abstract

Submarine groundwater discharge (SGD) is a recognized contributor to the hydrological and biogeochemical functioning of coral reef ecosystems located along coastlines. However, the distribution, size, and thermal properties of SGD remain poorly understood at most land–reef margins. We developed, deployed, and demonstrated an [...] Read more.

Submarine groundwater discharge (SGD) is a recognized contributor to the hydrological and biogeochemical functioning of coral reef ecosystems located along coastlines. However, the distribution, size, and thermal properties of SGD remain poorly understood at most land–reef margins. We developed, deployed, and demonstrated an operational method for airborne detection and mapping of SGD using the 200 km coastline of western Hawai‘i Island as a testing and analysis environment. Airborne high spatial resolution (1 m) thermal imaging produced relative sea surface temperature (SST) maps that aligned geospatially with boat-based transects of SGD presence–absence. Boat-based SST anomaly measurements were highly correlated with airborne SST anomaly measurements (R² = 0.85; RMSE = 0.04 °C). Resulting maps of the relative difference in SST inside and outside of SGD plumes, called delta-SST, revealed 749 SGD plumes in 200 km of coastline, with nearly half of the SGD plumes smaller than 0.1 ha in size. Only 9% of SGD plumes were ≥1 ha in size, and just 1% were larger than 10 ha. Our findings indicate that small SGD is omnipresent in the nearshore environment. Furthermore, we found that the infrequent, large SGD plumes (>10 ha) displayed the weakest delta-SST values, suggesting that large discharge plumes are not likely to provide cooling refugia to warming coral reefs. Our operational approach can be applied frequently over time to generate SGD information relative to terrestrial substrate, topography, and pollutants. This operational approach will yield new insights into the role that land-to-reef interactions have on the composition and condition of coral reefs along coastlines. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

16 pages, 3021 KiB

Open AccessArticle

Elucidating Temporal Patterns in Coral Health and Assemblage Structure in Papahānaumokuākea

by Atsuko Fukunaga, Kailey H. Pascoe, Randall K. Kosaki and John H. R. Burns

J. Mar. Sci. Eng. 2024, 12(8), 1267; https://doi.org/10.3390/jmse12081267 - 28 Jul 2024

Viewed by 923

Abstract

Coral reefs worldwide are under increasing levels of pressure due to global and local stressors. Long-term monitoring of coral reefs through repeated observations at fixed survey sites allows scientists to assess temporal patterns in coral-reef communities and plays important roles in informing managers [...] Read more.

Coral reefs worldwide are under increasing levels of pressure due to global and local stressors. Long-term monitoring of coral reefs through repeated observations at fixed survey sites allows scientists to assess temporal patterns in coral-reef communities and plays important roles in informing managers of the state of the ecosystems. Here, we describe coral assemblages in Papahānaumokuākea, the largest contiguous fully protected marine conservation area in the United States, using long-term monitoring data collected from 20 permanent (fixed) sites at three islands/atolls, Lalo, Kapou and Manawai, between 2014 and 2021. Significant temporal shifts in coral colony composition were detected at some of the monitoring sites, which were attributed to the impact of a mass coral bleaching event in 2014 and Hurricane Walaka in 2018. In particular, the bleaching affected multiple sites at Kapou and one site at Manawai where coral assemblages shifted from the Montipora dilatata/flabellata/turgescens complex to M. capitata dominance; despite being the dominant species at multiple monitoring sites prior to the bleaching, the M. dilatata/flabellata/turgescens complex has not been recorded at any of our monitoring sites in recent years. Coral conditions, such as bleaching, predation, subacute tissue loss, Porites pigmentation response and trematodiasis, did not show differences in the occurrence among the three islands/atolls once the site and temporal variabilities, as well as environmental covariates for bleaching, were considered. Coral genera, however, exhibited different sensitivities to these conditions. These findings highlight the importance of continuing coral reef monitoring at the species level, covering a broad range of coral assemblage compositions and habitat types in Papahānaumokuākea. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

Figure 1
Map of the Hawaiian Archipelago (bottom right) and the locations of Manawai, Lalo, Kapou, and aerial imagery of Manawai (top left), Lalo (top right) and Kapou (bottom left) showing the 20 permanent monitoring sites. Full article ">Figure 2
Hierarchical clustering with Type 1 SIMPROF test identifying the grouping structure of coral assemblages at Lalo. Dotted red branches show internally homogeneous structures. Square-root transformed percent coral colony compositions (red gradient ranging from 0 to 10) are shown for all coral species that were identified to characterize the grouping structure using SIMPER analyses, including those for Kapou and Manawai. Those specific to Lalo are mark by “*”. Species abbreviations are ACYT—Acropora cytherea, COCE—Cyphastrea ocellina, FSCU—Lobactis scutaria, MCAP—Montipora capitata, MFLA—Montipora dilatata/flabellata/turgescens complex, MINC—Montipora incrassate, MPAT—Montipora patula, PBRI—Porites brighami, PCOM—Porites compressa, PDAM—Pocillopora damicornis, PLIC—Porites lichen, PLIG—Pocillopora ligulata, PLOB—Porites lobata, PMEA—Pocillopora meandrina and PSTE—Psammocora stellata. Full article ">Figure 3
Hierarchical clustering with Type 1 SIMPROF test identifying the grouping structure of coral assemblages at Kapou. Dotted red branches show internally homogeneous structures. Square-root transformed percent coral colony compositions are shown for all coral species that were identified to characterize the grouping structure using SIMPER analyses, including those for Lalo and Manawai. Ones specific to Kapou are mark by “*”. See <a href="#jmse-12-01267-f002" class="html-fig">Figure 2</a> for species abbreviations. Full article ">Figure 4
Hierarchical clustering with Type 1 SIMPROF test identifying the grouping structure of coral assemblages at Manawai. Dotted red branches show internally homogeneous structures. Square-root transformed percent coral colony compositions are shown for all coral species that were identified to characterize the grouping structure using SIMPER analyses, including those for Lalo and Kapou. Ones specific to Manawai are mark by “*”. See <a href="#jmse-12-01267-f002" class="html-fig">Figure 2</a> for species abbreviations. Full article ">Figure 5
Plots showing the percentage of coral colonies exhibiting bleaching, predation, subacute tissue loss, Porites pigmentation response or trematodiasis at each region (island/atoll) each year. The percentage values were calculated for each site within each region. Note that the sites that were surveyed each year varied (see <a href="#jmse-12-01267-t001" class="html-table">Table 1</a>). In Manawai, there was only one site (PHR tc26) surveyed in 2014, and no surveys were done in 2021. Full article ">Figure 6
Interval plot (a) showing the estimated coefficients for the final bleaching occurrence model selected based on LOO-CV and conditional effect plots for (b) the interaction between standardized sea surface temperature and standardized wind speed and (c) the interaction between standardized sea surface temperature and standardized chlorophyll a concentration. The interval plot shows the median estimates (circles) and 50 and 95 percentiles (thick and thin lines) of the coefficients including standardized sea surface temperature (sst), standardized surface wind speed (wind), standardized chlorophyll a concentration (chlorophyll), their interactions and the fixed factor of genus. For the fixed factor of genus, Porites was treated as the reference factor level. The standardized sea surface temperature of 0 corresponds to 26.42 °C with 1 unit of change corresponding to a difference in 1.41 °C (see Methods). Full article ">Figure 7
Interval plot showing the estimated coefficients for the final models based on LOO-CV for (a) predation and (b) subacute tissue loss. For the fixed effects of genus, Porites was treated as the reference factor level. Full article ">Figure 8
Interval plot showing the estimated coefficients for the final models based on LOO-CV for (a) Porites pigmentation response and (b) trematodiasis. Full article ">

18 pages, 13360 KiB

Open AccessArticle

Identification of Suitable Mangrove Distribution Areas and Estimation of Carbon Stocks for Mangrove Protection and Restoration Action Plan in China

by Bingbin Feng, Yancheng Tao, Xiansheng Xie, Yingying Qin, Baoqing Hu, Renming Jia, Lianghao Pan, Wenai Liu and Weiguo Jiang

J. Mar. Sci. Eng. 2024, 12(3), 445; https://doi.org/10.3390/jmse12030445 - 1 Mar 2024

Cited by 1 | Viewed by 2839

Abstract

Mangrove forests are significant blue carbon pools on the Earth with strong carbon sequestration capacity and play an important role in combating climate change. To improve the capacity of regional carbon sinks, China has implemented a Special Action Plan for Mangrove Protection and [...] Read more.

Mangrove forests are significant blue carbon pools on the Earth with strong carbon sequestration capacity and play an important role in combating climate change. To improve the capacity of regional carbon sinks, China has implemented a Special Action Plan for Mangrove Protection and Restoration (2020–2025). In this context, based on the MaxEnt model, this study analyzed the important environmental factors affecting the distribution of mangrove forests, combined with the planning objectives and carbon density parameters of different regions; assessed the habitat suitability areas of China’s mangrove forests; and predicted their future carbon stock potential. The results showed the following: (1) Elevation was the most important factor affecting the overall distribution of mangrove forests in China, and the optimal elevation of mangrove distribution was 0.52 m. (2) The most suitable areas of mangrove forests in China were mainly distributed in Hainan, Guangxi, and Guangdong, which had great potential for carbon stock. Danzhou Bay and Hongpai Harbor in Hainan, Lianzhou Bay in Guangxi, and the Huangmao Sea in Guangdong are potential areas for habitat suitability but are not yet under high levels of protection. (3) Achieving the goals of this action plan was expected to increase carbon stocks by 4.13 Tg C. Other suitable areas not included in this plan could still increase carbon stocks by 7.99 Tg C in the long term. The study could provide a scientific basis for siting mangrove restoration areas and developing efficient management policies. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

62 pages, 34100 KiB

Open AccessArticle

Stronger Hurricanes and Climate Change in the Caribbean Sea: Threats to the Sustainability of Endangered Coral Species

by Edwin A. Hernández-Delgado, Pedro Alejandro-Camis, Gerardo Cabrera-Beauchamp, Jaime S. Fonseca-Miranda, Nicolás X. Gómez-Andújar, Pedro Gómez, Roger Guzmán-Rodríguez, Iván Olivo-Maldonado and Samuel E. Suleimán-Ramos

Sustainability 2024, 16(4), 1506; https://doi.org/10.3390/su16041506 - 9 Feb 2024

Cited by 2 | Viewed by 3493

Abstract

An increasing sea surface temperature as a result of climate change has led to a higher frequency and strengthening of hurricanes across the northeastern Caribbean in recent decades, with increasing risks of impacts to endangered corals and to the sustainability of coral reefs. [...] Read more.

An increasing sea surface temperature as a result of climate change has led to a higher frequency and strengthening of hurricanes across the northeastern Caribbean in recent decades, with increasing risks of impacts to endangered corals and to the sustainability of coral reefs. Category five Hurricanes Irma and María during 2017 caused unprecedented damage to coral reef ecosystems across northeastern Puerto Rico, including mechanical destruction, localized sediment bedload (horizontal sediment transport and abrasion), and burial by hurricane-generated rubble fields. Hurricanes inflicted significant site-, depth-, and life history trait-specific impacts to endangered corals, with substantial and widespread mechanical damage to branching species, moderate mechanical damage to foliose species, and moderate to high localized damage to small-sized encrusting and massive morphotypes due to sediment bedload and burial by rubble. There was a mean 35% decline in Acropora palmata live cover, 79% in A. cervicornis, 12% in Orbicella annularis, 7% in O. faveolata, 12% in O. franksi, and 96% in Dendrogyra cylindrus. Hurricane disturbances resulted in a major regime shift favoring dominance by macroalgae, algal turf, and cyanobacteria. Recovery from coral recruitment or fragment reattachment in A. palmata was significantly higher on more distant coral reefs, but there was none for massive endangered species. Stronger hurricanes under projected climate change may represent a major threat to the conservation of endangered coral species and reef sustainability which will require enhancing coral propagation and restoration strategies, and the integration of adaptive, ecosystem-based management approaches. Recommendations are discussed to enhance redundancy, rapid restoration responses, and conservation-oriented strategies. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

16 pages, 9775 KiB

Open AccessArticle

Land Use/Land Cover Changes in a Mediterranean Summer Tourism Destination in Turkey

by Ismail Cinar, Zeynep R. Ardahanlıoğlu and Süleyman Toy

Sustainability 2024, 16(4), 1480; https://doi.org/10.3390/su16041480 - 9 Feb 2024

Viewed by 1248

Abstract

Tourism contributes to national and local economies especially in the Mediterranean and Aegean coasts of Turkey including the study area, Fethiye-Göcek, Muğla in southwest Turkey. The study evaluates land use/land cover (LULC) changes driven by tourism development as a case considering the past [...] Read more.

Tourism contributes to national and local economies especially in the Mediterranean and Aegean coasts of Turkey including the study area, Fethiye-Göcek, Muğla in southwest Turkey. The study evaluates land use/land cover (LULC) changes driven by tourism development as a case considering the past (1995–2020) and future environmental impacts on the area. High-resolution remote sensing and some socio-economic data were employed to monitor the situation and causes of LULC changes using Normalised Difference Vegetation Index (NDVI) and Land Surface Temperature (LST). The results show a decrease in the size of water surface, forest and maquis lands due to tourism development together with an increase in urban fabrics and bare lands due to urbanisation and forest fires. A significant positive correlation was detected between the urbanisation rate, population size and built-up area as well as air temperature and LST. Rapid and unplanned tourism development boosted investments for infrastructure and facilities and thus increased the demands for lands. Such lands were mostly gained by filling the sea or transforming agricultural and greenhouse areas, forest and maquis-covered lands. The unplanned development of tourism and urban areas caused serious hazards to the natural and cultural areas which threaten the sustainability of tourism. Planning suggestions are proposed to decision makers like coordination works for sustainable and responsible tourism development. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

10 pages, 8386 KiB

Open AccessArticle

Artificial Reef Deployment Reduces Diving Pressure from Natural Reefs—The Case of Introductory Dives in Eilat, Red Sea

by Nadav Shashar, Asa Oren, Re’em Neri, Omer Waizman, Natalie Chernihovsky and Jenny Tynyakov

Oceans 2024, 5(1), 71-80; https://doi.org/10.3390/oceans5010005 - 7 Feb 2024

Viewed by 2862

Abstract

Artificial reefs have been suggested as alternative dive sites to mitigate human pressure on natural reefs. Despite the conceptual appeal of artificial reefs, there is a paucity of empirical evidence regarding their effectiveness in achieving this objective. Here, we report that a small [...] Read more.

Artificial reefs have been suggested as alternative dive sites to mitigate human pressure on natural reefs. Despite the conceptual appeal of artificial reefs, there is a paucity of empirical evidence regarding their effectiveness in achieving this objective. Here, we report that a small artificial reef deployed adjacent to a local coral marine protected area caused a shift in the routes taken by introductory dives and nearly eliminated their visitations to the natural fringing reef within the MPA. This behavioral shift among divers persisted for more than a decade following the AR deployment. These findings underscore the efficacy of well-designed and appropriately located artificial reefs as valuable instruments in the conservation of coral reefs. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Graphical abstract

18 pages, 3607 KiB

Open AccessArticle

Assessing the Fishing Impact on the Marine Ecosystem of Guishan Island in the Northeastern Waters of Taiwan Using Ecopath and Ecosim

by Chien-Pang Chin, Kuan-Yu Su and Kwang-Ming Liu

J. Mar. Sci. Eng. 2023, 11(12), 2368; https://doi.org/10.3390/jmse11122368 - 15 Dec 2023

Viewed by 1316

Abstract

The northeastern waters of Guishan Island constitute one of the crucial fishing grounds for coastal trawl fishery in Taiwan and have been exploited for many decades. To construct the marine ecosystem and to examine the interactions among trophic levels of fisheries resources in [...] Read more.

The northeastern waters of Guishan Island constitute one of the crucial fishing grounds for coastal trawl fishery in Taiwan and have been exploited for many decades. To construct the marine ecosystem and to examine the interactions among trophic levels of fisheries resources in the waters of Guishan Island, historical catch, catch composition, biological information, fishing effort, environmental data such as sea surface temperature, salinity, and nutrients were analyzed using Ecopath with Ecosim. The results indicated that the longline and drift net fisheries have a very minor incidental catch of cetaceans, with a fishing mortality (F) of 0.01 year⁻¹ and an exploitation rate (E) of 0.03. The F and E were 0.308 year⁻¹ and 0.617 for small skates and rays, and were 0.261 year⁻¹ and 0.580, respectively, for small sharks. The F and E of the dolphinfish, Coryphaena hippurus, an important pelagic species, were 0.411 year⁻¹ and 0.245, respectively. Fisheries had negative impact on major commercial species except the dolphinfish and the oil fish, Lepidocybium spp., which benefited from the reduction of their predators or competitors. The keystone species of the Guishan Island marine ecosystem is phytoplankton, which has the lowest trophic level and great biomass, and is an important energy source of the ecosystem. The influences of zooplankton and anchovy rank as second and third, respectively, with regard to the keystone species in the ecosystem due to their great biomass. Regarding the biomass of less abundant species, carangids had the highest influence followed by hairtail due to their feeding habits. The results of simulations using Ecosim indicated that the hairtail, small sharks, skates and rays, mackerels, and marine eels will benefit if fishing efforts are reduced by 30%. On the other hand, the biomass of phytoplankton, zooplankton, demersal benthivores, and shrimps will decrease due to the increase in the biomass of their predators. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

19 pages, 11393 KiB

Open AccessReview

Development Trends, Current Hotspots, and Research Frontiers of Oyster Reefs: A Bibliometric Analysis Based on CiteSpace

by Jie Cheng, Duian Lu, Li Sun, Wei Mo, Mengnan Shen, Ming Li, Chenyang Li, Ming Zhang, Jun Cheng, Degang Wang and Yonghua Tan

Water 2023, 15(20), 3619; https://doi.org/10.3390/w15203619 - 16 Oct 2023

Cited by 1 | Viewed by 2244

Abstract

The ocean is the largest reservoir on Earth. With the scarcity of water resources, the destruction of the benign cycle of the marine ecosystem would seriously impact people’s quality of life and health. Oyster reefs, the world’s most endangered marine ecosystems, have been [...] Read more.

The ocean is the largest reservoir on Earth. With the scarcity of water resources, the destruction of the benign cycle of the marine ecosystem would seriously impact people’s quality of life and health. Oyster reefs, the world’s most endangered marine ecosystems, have been recognized as a global issue due to their numerous essential ecological functions and provision of various ecosystem services. As a result, interest in oyster reef research has been steadily increasing worldwide in recent decades. The goal of this study is to assess the knowledge structure, development trends, research hotspots, and frontier predictions of the global oyster reef research field. Based on 1051 articles selected from the Web of Science Core Collection from 1981 to 2022, this paper conducted a visual analysis of oyster reef ecosystems conservation, restoration, and management. Specifically, it examined research output characteristics, research cooperation networks, highly cited papers and core journals, and keywords. Results indicate a steady rise in research interest in oyster reefs over the past 40 years, with notable acceleration after 2014. Authoritative experts and high-impact organizations were also identified. This paper outlines habitat conservation and restoration, ecosystem services, and the impacts of climate change as the primary research hotspots and frontiers. This paper provides valuable guidance for scholars and regulators concerned about oyster reef conservation to conduct research on oyster reefs. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

14 pages, 23469 KiB

Open AccessTechnical Note

Exploring New Frontiers in Coral Nurseries: Leveraging 3D Printing Technology to Benefit Coral Growth and Survival

by Ofer Berman, Natalie Levy, Haim Parnas, Oren Levy and Ezri Tarazi

J. Mar. Sci. Eng. 2023, 11(9), 1695; https://doi.org/10.3390/jmse11091695 - 28 Aug 2023

Cited by 5 | Viewed by 2723

Abstract

Coral nurseries and associated techniques are the most common and widespread reef restoration methods worldwide. Due to the rapid decline of coral reefs, coral nurseries need to be eco-friendlier and adapted for effective upscaling to support large restoration projects. We suggest new design [...] Read more.

Coral nurseries and associated techniques are the most common and widespread reef restoration methods worldwide. Due to the rapid decline of coral reefs, coral nurseries need to be eco-friendlier and adapted for effective upscaling to support large restoration projects. We suggest new design and fabrication processes associated with coral gardening and transplantation with 3D printing technology to offer a beneficial solution for growing coral fragments in on-land and underwater nurseries. We describe multiple combinations of building nurseries through the integration of biomimetic substrates and novel solutions for attaching coral fragments. Our methods are supported with supplemental testing of two hybrid substrate designs and coral mounting structures, building upon previous studies in the Gulf of Eilat/Aqaba (GoE/A), Red Sea. We identified and quantified marine invertebrates colonizing the surfaces of our substrates with environmental DNA (eDNA) by targeting the mitochondrial COI gene. We evaluated our coral fragments with and without our mounting structures to obtain an indication of total protein as a proxy for tissue health. We demonstrate the ability to design hybrid nurseries with custom mounting structures using biomimetic substrates, such as large ceramic artificial reefs, or with an interlocking mesh for holding numerous fragments to maximize out-planting efforts. We propose several methods for both land and underwater nurseries catered to various restoration initiatives for cost-effective up-scaling to meet the demands of global reef restoration. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

Figure 1
Biomimetic settlement tile adapted with mounting structure. (A) The square ceramic tile after bisque firing, and the initial design of the mounting structure custom-made to fit specific holes in the tiles. (B) Custom mounting structure with coral skeleton; the flexible mounting structures are printed with bottom and top overhangs which help to secure it to the tile. (C) The square tile submerged with the planted fragments (not all attached with the mounting structure). (D) Conceptualization of a horizontal floating coral nursery composed of square ceramic tiles and custom mounting structures. Full article ">Figure 2
Complex 3DP settlement tile configurations with mounting structure. (A) The round 3DP ceramic tile after bisque firing, with second-version universal mounting structures, exhibiting a more advanced design. Mounting structures are anchored to the holes in the tiles. (B) Underwater testing of the design of the mounting structure to attach coral fragments (in the Northern Red Sea, 2023). (C) Testing different infill patterns of the round tiles with fragments (without inserts) underwater (in the Maldives, 2022). (D) Conceptualization of a vertical floating coral nursery made up of round ceramic tiles and universal mounting structures. Full article ">Figure 3
Proof of concept of coral nursery mesh design consisting of universal mounting structures. (A) First-generation design of the universal mounting structure, 3DP modular nylon housing, and a 3DP jig to die-cut the inner wall to release the bristles. (B) Overview of the flexible nursery prototype, which in a 100 m<math display="inline"><semantics> <msup> <mrow/> <mn>2</mn> </msup> </semantics></math> floating nursery that could contain up to 90,000 fragments. (C) Close-up of a coral skeleton secured to the meshed mounting structure. (D) Testing the prototype underwater with live coral fragments. The design of the mesh mounting structures can wrap around existing artificial structures such as concrete columns or piers, turning them into a nursery. Full article ">Figure 4
Total number of sequences of phyla found on parametric square tiles. Phyla were detected from eDNA present only on tiles at two study sites in the GoE/A after quality control. Pictures represent the organisms from each phyla to show habitat partitioning on tiles (adapted with permission from Ref. [<a href="#B17-jmse-11-01695" class="html-bibr">17</a>]; Science of The Total Environment; Elsevier; 2023). Full article ">Figure 5
Total protein content from the tissues of three branching corals. Baseline corals represent the fragments before they were attached to substrates (tiles). The substrate treatment is the 6 months after they were mounted to tiles. Asterisks represent the level of p-value significance: p < 0.01 (*) and p < 0.001 (**). Dots represent replicates. Full article ">Figure 6
Visualization of a benthic organism succession on a ceramic reef with planted fragments (adapted with permission from Ref. [<a href="#B6-jmse-11-01695" class="html-bibr">6</a>]; Science of The Total Environment; Elsevier; 2022). (A) Newly deployed biomimetic AR with fragments. (B) Projection of a six-month- to one-year-old AR with growing fragments, with a gradual accumulation of marine invertebrates, microorganisms, and algae. (C) Fully covered coral reef ecobiome growing on the AR with larger and diverse coral fragments. Full article ">

18 pages, 2051 KiB

Open AccessArticle

Heavy Metal Content in Macroalgae as a Tool for Environmental Quality Assessment: The Eastern Gulf of Finland Case Study

by Yulia I. Gubelit, Tatiana D. Shigaeva, Valentina A. Kudryavtseva and Nadezhda A. Berezina

J. Mar. Sci. Eng. 2023, 11(9), 1640; https://doi.org/10.3390/jmse11091640 - 23 Aug 2023

Cited by 3 | Viewed by 1318

Abstract

Macroalgae are widely used for bioindication and assessment; however, in the case of pollutants of different origin, it is still unclear which contaminants in thalli can be regarded as indicative because too many factors influence the ability of algae to uptake them. The [...] Read more.

Macroalgae are widely used for bioindication and assessment; however, in the case of pollutants of different origin, it is still unclear which contaminants in thalli can be regarded as indicative because too many factors influence the ability of algae to uptake them. The present study is a part of an international HAZLESS project and was conducted in the eastern Gulf of Finland (GoF). The main goal of our study was the application of metal concentrations in macroalgae as a tool for environmental quality assessment. To achieve this goal, we calculated the threshold metal concentrations in macroalgae (Cladophora glomerata) and compared our obtained values with actual concentrations. We found significant Spearman correlations in May between metals in sediments and pore water (−0.73 for Zn, −0.62 for Cd, 0.85 for Pb) and also between metals in algae and metals in pore water (1 for Cu and Cd, 0.98 for Zn and Pb). In July, Pb in algae were significantly correlated with Pb in pore water (0.88). The application of the calculated environmental quality standard (EQS_MPC) for macroalgae has shown moderate pollution by Cu and Pb in the coastal zone of the eastern GoF. This was confirmed by an assessment based on the comparisons of metal concentrations in water with Environmental Quality Standards for water (EQS_w). However, differences in the bioaccumulation factor and EQS_MPC between May and July have shown that it is necessary to compare samples taken during the same period every year for adequate results in long-term monitoring. Considering the sensitivity of accumulating processes to the surrounding environment, we believe that in the case of habitats with diverse conditions, even for the same species of algae, threshold values should be calculated and used individually for every habitat. Our results have shown that this approach can be widely used for an assessment of environmental quality via metal concentrations in opportunistic macroalgae and can be recommended for further use. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

Figure 1
Schematic map of the eastern Gulf of Finland. Sampling sites are marked by numbers. Full article ">Figure 2
Metal distribution in the water on study sites of the EGoF in May 2019. *—significantly higher; *—significantly lower. Full article ">Figure 3
Metal distribution in the water on study sites of the EGoF in July 2019. *—significantly higher. Full article ">Figure 4
Metal distribution in sediments on study sites of the EGoF in May 2019. *—significantly higher. Full article ">Figure 5
Metal content in biomass of Cladophora glomerata in May 2019. *—significantly higher. Full article ">Figure 6
Metal content in algal biomass in July 2019. *—significantly higher. Full article ">Figure 7
Principal component and classification analysis for main hydrochemical parameters (Eh, Temperature, pH in sediments (pHsed), water pH (pHw), salinity) and metal distribution in sediments (Me), water (Me1), pore water (Me2), and algae (Me3) in May 2019. Full article ">Figure 8
Principal component and classification analysis for main hydrochemical parameters (Eh, Temperature, water pH (pH), salinity) and metal distribution in water (Me1), pore water (Me2), and algae (Me3) in July 2019. Full article ">

19 pages, 2879 KiB

Open AccessArticle

Estimate of Cetacean and Shark Depredations in the Small-Scale Longline Fishery in the Southeastern Waters of Taiwan

by Kwang-Ming Liu, Kuan-Yu Su and Chien-Pang Chin

J. Mar. Sci. Eng. 2023, 11(6), 1233; https://doi.org/10.3390/jmse11061233 - 15 Jun 2023

Viewed by 1510

Abstract

Cetacean and shark depredations in a small-scale longline fishery in the southeastern Taiwan waters were estimated based on interviews of 21 fishermen and logbooks of 12 sampling vessels, including 649 operations (681,310 hooks) from October 2009 to December 2010. Cetacean depredations were more [...] Read more.

Cetacean and shark depredations in a small-scale longline fishery in the southeastern Taiwan waters were estimated based on interviews of 21 fishermen and logbooks of 12 sampling vessels, including 649 operations (681,310 hooks) from October 2009 to December 2010. Cetacean depredations were more serious than shark depredations, with damage rates of 19.26% and 11.56%, respectively. The depredation rates in number and weight from cetaceans were estimated to be 2.21% and 3.23%, respectively, and were significantly higher than those from sharks, which were estimated to be 0.51% and 0.47%, respectively. The depredation indices from cetacean and shark were estimated to be 0.93 and 0.22 per 1000 hooks, respectively. The dolphinfish and yellowfin tuna were the top two species depredated by cetaceans and sharks. The annual economic loss of the small-scale longline fishery due to cetacean and shark depredations was estimated to be USD 441.9 thousand and USD 58.8 thousand, respectively, which corresponded to 4.5% and 0.6% of the total sales of the longline fishery at Hsinkang fishing port, southeastern Taiwan. The catch in number of dolphinfish and the operation depth were significant factors that affected cetacean depredations. Full article

(This article belongs to the Topic Conservation and Management of Marine Ecosystems)

► Show Figures

Figure 1

Figure 1
The fishing area and fishing efforts of the small-scale tuna longline sampling vessels in this study. Full article ">Figure 2
The percentage of species-specific catch in number (a) and catch in weight (b) of sampling vessels. Full article ">Figure 3
The species-specific catch in number from March to September (a) and from October to February (b), and the catch in weight from March to September (c) and from October to February (d) of sampling vessels in different fishing seasons. The left side of the Y-axis is for dolphinfish, and the right side is for other species. Full article ">Figure 4
A catch depredated by cetacean (a) and shark (b). Full article ">Figure 5
The depredation rate in number (DRN) of cetaceans (a) and sharks (b), and depredation index (DI) of cetaceans (c) and sharks (d) by 0.25° × 0.25° grid. Full article ">Figure 6
The percentage of species-specific production (a) and value (thousand USD) (b) at Hsinkang fishing port. Full article ">Figure 7
Species-specific economic loss due to depredations from cetaceans (a) and sharks (b) of the sampling vessels. Full article ">

Topic Menu

Topic Editors

Conservation and Management of Marine Ecosystems

Topic Information

Keywords

Participating Journals

Published Papers (14 papers)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI