Exclusive Economic Zone Research Articles

Revision of the deep-water cone snail fauna from New Caledonia (Gastropoda, Conoidea)

The present work reviews the deep-water cone fauna of New Caledonia and its Economic Exclusive Zone. It is based on the material collected for more than 40 years by oceanographic expeditions in the deep waters surrounding New Caledonia, organized by the Muséum national d’histoire naturelle-Paris/ORSTOM, then Institut de Recherche pour le Développement, in the framework of the Tropical Deep-Sea Benthos programme. A total of 2377 lots containing 5113 specimens collected in depths between 100 and 1260 m have been examined. About 770 specimens were collected live, and allowed for radular and DNA studies. A phylogenetic analysis, based on the cox1 gene, of the deep-water cone snail fauna of New Caledonia is presented, along with a detailed, fully illustrated taxonomic account with data on geographic and bathymetric distribution and radular morphology. A total of 76 different species of cone snails were identified among the collected material. Of these, 22 corresponded to typical shallow water species, which were most likely translocated into deeper water, whereas 54 could be considered true components of the deep water (below 100 m) cone snail fauna. Species of the genus Profundiconus represent 22%, whereas those of the genera Conasprella and Conus represent 28% and 50%, respectively. Eleven deep water cone species can be considered as endemic to the New Caledonia EEZ, representing 20.3% of the total. The most abundant species found (more than 400 specimens each) were Conus (Afonsoconus) bruuni, Conasprella (Boucheticonus) alisi, Conasprella (Conasprella) boucheti, and Profundiconus vaubani. The new species Conus (Taranteconus) samadiae sp. nov. is hereby described.

HUMAN AWARENESS TO ENVIRONMENTAL PROTECTION IN SMALL ISLANDS DEVELOPING STATES (SIDS): THE MAURITIAN CASE STUDY

This contextualised paper deals with environmental protection to enhance socio-economic development in SIDS with particular reference to the small Republic of Mauritius. With the relevant legal and regulatory framework it investigates environmental protection in SIDS with particular attention drawn to the small Republic of Mauritius and its huge Exclusive Economic Zone (EEZ) in the Indian Ocean, and its blue economy would generate trillion of dollars provided the EEZ is not over-exploited otherwise mankind would pay it in a very costly way. The Republic of Mauritius is also a very interesting case study because the Mauritius and its legal system inherited both French Civil Law (1715-1810) and English Common Law (1810-1968) during its two successive colonisation with a written Constitution 1968 which has no provision on the right to protection of the environment and the Mauritian legislator has neither reacted promptly to implement same in the Constitution 1968 compared to other Small Island Developing States (Maldives, Seychelles) albeit there is a plethora of legislations and regulations to protect the environment in a country where there is room for improvement in various key sectors for its socio-economic development and to protect the island against nature’s wrath, droughts, food and water insecurity. However, with the exploitation of petrol and oil for exploitation, activists and human rights fighters found that there might be an impact both in its green and blue economy provoking nature’s wrath with tsun amis, volcanoes or cyclones which are becoming more frequent in the Indian Ocean. It is time to react fast and promptly and this paper might enlighten a little more of human’s irresponsibility.

Vietnam - Indonesia Cooperation on Sea Definition: Practice and Meaning

Vietnam has a long coastline and a large sea area, with several islands and archipelagoes, particularly the Hoang Sa and Truong Sa archipelagoes. Therefore, Vietnam's main objectives during the process of national construction and growth are maritime security in particular and the safeguarding of the integrity of its land, sea, and airspace. Vietnam consistently emphasizes cooperation with regional nations to achieve this objective in particular. According to the United Nations Convention on the Law of the Sea 1958, Vietnam shares maritime borders with China and Cambodia, and shares continental shelf boundaries with China, Indonesia, Malaysia, Cambodia and Thailand. Currently, according to the United Nations Convention on the Law of the Sea (UNCLOS) in 1982, the boundary of Vietnam's exclusive economic zone and continental shelf is expanded and adjacent to many countries. Besides the well-defined sea areas with neighboring countries (Thailand, Indonesia), Vietnam is still negotiating some of the remaining sea ares with China, Malaysia and Cambodia. Among the countries with which Vietnam has completed negotiations on maritime delimitation, the cooperation between Vietnam and Indonesia on maritime delimitation is very important, creating a premise for a clearer maritime boundary delimitation with other countries and contributing to promoting the development of the Vietnam - Indonesia Strategic Partnership to a new level. This article will present and analyze the cooperation relationship on maritime delimitation between Vietnam and Indonesia from the perspective of international studies.

Ecosystem Management Policy Implications Based on Tonga Main Tuna Species Catch Data 2002–2018

Despite the crucial role played by international and regional tuna fisheries in facilitating the successful implementation of the ecosystem approach to fisheries management, there exist disparities in viewpoints among these stakeholders, resulting in gaps between regional fisheries management and local communities. Nevertheless, the Tongan government, under the Ministry of Fisheries, is dedicated to the efficient management of its tuna resources, aiming to establish it as the preferred and optimal approach for ensuring the long-term sustainability of its tuna fisheries and the ecosystem services they provide to the community. Recognizing that an appropriate legal, policy and institutional framework is in place for sustainable management of tuna, the first part of this paper presents a review of current Tonga fisheries laws and policies for its tuna fisheries. This review reflects the implementation of an information-based management framework, namely the Tonga National Tuna Fishery Management and Development Plan. The tuna fisheries in Tonga mainly catch albacore (Thunnus alalunga), bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin (Thunnus albacares) tuna. These tuna species are caught within Tonga’s exclusive economic zones and play a crucial role in the country’s economy; hence, it is crucial to examine the spatio-temporal distributions of their catch in relation to their environmental conditions. In pursuit of this goal, the tasks of mapping (i) the spatio-temporal distribution of catch landed at ports and (ii) the spatio-temporal of environmental conditions were performed. The study utilizes longline catch per unit effort data spanning from 2002 to 2018 for albacore, bigeye, skipjack, and yellowfin tuna. It also incorporates data on environmental conditions, including sea surface temperature, sea surface chlorophyll, sea surface current, and sea surface salinity. Additionally, the El Nino Southern Oscillation Index is mapped in relation to catch data to examine the potential effects of climate change on the tuna catch. Results show that bigeye, skipjack, and yellowfin CPUE show a central–northernmost distribution and are primarily caught between latitudes 14° S–22° S, while albacore, shows a central–southern distribution. The highest CPUE for all species are in latitudes 15.5° S–22.5° S and longitudes 172.5° W–176.5° W. The data indicate that sea surface current velocities range from −0.03 to 0.04 ms−1, sea surface salinity ranges from 34.8 to 35.6 PSU, sea surface chlorophyll concentration varies from 0.03 to 0.1 mg m−3, and sea surface temperature fluctuates seasonally, ranging from 18 °C to 30 °C. Mapping also reveals that times of reduced catches in Tonga coincide with periods of moderate to strong El Nino events from 2002 to 2018.

Mexico on Track to Protect 30% of Its Marine Area by 2030

Mexico has committed to protecting 30% of its marine territory by 2030 to comply with Target 3 of the Kunming–Montreal Global Biodiversity Framework, adopted during the 15th Conference of the Parties to the Convention on Biological Diversity. In this paper, we demonstrate the feasibility of meeting this commitment by determining the marine extent of conservation measures based on legally established Marine Protected Areas and areas that meet the criteria to be considered as Other Effective area-based Conservation Measures (OECMs) and determining the marine extent of areas proposed in various conservation planning exercises that can be created as any of the area-based instruments that exist in Mexico. The total coverage of existing and proposed areas was calculated by merging the dataset to remove duplicates and dissolving the boundaries between polygons to determine the total area. Spatial analysis was carried out in ArcGIS using geoprocessing tools. Currently, more than 25% of Mexico’s marine area is legally protected or conserved, with federal marine protected areas covering more than 22% of the Exclusive Economic Zone. The legally established areas that can be considered OECMs cover about 3% of the marine territory. We found that more than 9% of Mexico’s Economic Exclusive Zone contains areas of high conservation importance that are not covered by any area-based instrument. This study shows that Mexico has the potential to protect or conserve 32.8% of its marine territory by 2030.

Once upon a century, the Egyptian Mediterranean fisheries (1920–2019), as affected by ‘fishing down’ and climate change

Fishing has been practiced in Egypt for several millennia in the Nile and various lakes, the Mediterranean, and the Red Sea. Here, the marine fisheries catch from the area corresponding to Egypt's current Exclusive Economic Zone in the Mediterranean were re-estimated for the shorter period from 1920 to 2019. This study covers reported and formerly unreported commercial and non-commercial, small- and large-scale fisheries catches and estimated discards. Given that the Food and Agriculture Organization (FAO) has been publishing annual fisheries statistics only since 1950, the comparison of reconstructed marine catch data to the FAO-reported catch data covers only the period from 1950 to 2019. Reconstructed marine fisheries catches for the Egyptian Mediterranean EEZ for 1950–2019 were about 1.3 times the reported catch by the FAO on behalf of Egypt. This discrepancy is due to a combination of elements, mainly unreported commercial industrial and artisanal catches and industrial discards.Several events have drastically affected the Mediterranean marine fisheries of Egypt, such as the opening of the Suez Canal, the Aswan High Dam, and, more recently, the Egyptian Revolution of 2011. Climate change has also influenced the overall productivity as well as the species composition of the catch. The Mean Temperature of Catch (MTC) from the Mediterranean Egyptian waters has increased by an annual average of 0.07 °C per year since 1987. The Marine Trophic Index (MTI) showed that ‘fishing down’ has occurred in Egypt's Mediterranean waters since the early 1970s.The dataset provided by this study can be applied to catch-based indicators to better assess the Egyptian Mediterranean fish stocks. This would help improve fisheries management in the region and ensure the sustainability of the Egyptian Mediterranean fisheries.

Fishery catch is affected by geographic expansion, fishing down food webs and climate change in Aotearoa, New Zealand.

Historical fishing effort has resulted, in many parts of the ocean, in increasing catches of smaller, lower trophic level species once larger higher trophic level species have been depleted. Concurrently, changes in the geographic distribution of marine species have been observed as species track their thermal affinity in line with ocean warming. However, geographic shifts in fisheries, including to deeper waters, may conceal the phenomenon of fishing down the food web and effects of climate warming on fish stocks. Fisheries-catch weighted metrics such as the Mean Trophic Level (MTL) and Mean Temperature of the Catch (MTC) are used to investigate these phenomena, although apparent trends of these metrics can be masked by the aforementioned geographic expansion and deepening of fisheries catch across large areas and time periods. We investigated instances of both fishing down trophic levels and climate-driven changes in the geographic distribution of fished species in New Zealand waters from 1950-2019, using the MTL and MTC. Thereafter, we corrected for the masking effect of the geographic expansion of fisheries within these indices by using the Fishing-in-Balance (FiB) index and the adapted Mean Trophic Level (aMTL) index. Our results document the offshore expansion of fisheries across the New Zealand Exclusive Economic Zone (EEZ) from 1950-2019, as well as the pervasiveness of fishing down within nearshore fishing stock assemblages. We also revealed the warming of the MTC for pelagic-associated fisheries, trends that were otherwise masked by the depth- and geographic expansion of New Zealand fisheries across the study period.

The Exclusive Economic Zone in the Law of the Seas Particular Reference to the Omani EEZ

The Exclusive Economic Zone in the Law of the Seas Particular Reference to the Omani EEZ

Dimensioning and optimization of multi-source offshore renewable energy parks

Multi-source offshore renewable energy parks, consisting of wind, solar and wave converters, can utilize the available offshore area much more efficiently than single source wind parks. They can also produce power with a higher capacity factor than single source parks, utilizing the available grid connection more efficiently. Dimensioning and financial optimization of such parks will be driven by geographic constraints like available area, water depths, shipping lanes, exclusion zones etc., but also by the available resources of wind, solar and wave power. Another major driver in the optimization will be the electricity price. With the raising share of weather dependent renewables in the electricity mix, the electricity price will become more volatile. Therefore, an optimized design process of a multi-source park should also incorporate a pricing mechanism that can produce hourly electricity prices based on actual weather conditions. The paper will present the results of a numerical model that can integrate solar and wave power in a wind park area as well as optimize the export cable capacity. Battery storage can be added to this multi-source park to shift part of the production to hours with higher electricity prices. A case study has been performed for the planned offshore wind park TNW, North of the Dutch Waddeneilanden. Since such a multi-source park will have an expected lifetime of about 30 years, it will even reach the year 2050, in which weather dependent renewable energy will be much more dominant than today, with far stronger electricity price volatility. For the electricity price calculation, assumptions are made for the installed base of solar, wind and wave power in the whole of The Netherlands, as well as the geographic spread of this installed base over the land area and the offshore exclusive economic zone in the North Sea. This installed base is simplified by concentrating it in about ten locations divided over this area. Other necessary assumptions are the future electricity demand pattern, the future capacity of the interconnections with the surrounding countries and the capacity of the flexible load that will be available at that time (electric cars, electric heaters etc.). From literature, the cost of conventional power fueled by natural gas and/or hydrogen is derived which serves as back up power for hours with low wind, solar and wave power production. Based on all these assumptions, a pricing curve is constructed reaching from sub zero at abundant renewable supply to a maximum value at zero renewable supply. With the model, scenarios of future developments in installed wind, solar and wave power, but also in e.g. electric cars, electric heaters and other flexible loads, can be examined and the sensitivity of the optimization of the multi-source park design can be determined. The relevance of wave power can be determined from the average price per MWh that wave power can earn compared to wind and solar.

Mapping of potential fishing areas of Sardinella aurita in the Ivorian exclusive economic zone (EEZ) from 2010 to 2020

Mapping of potential fishing areas of Sardinella aurita in the Ivorian exclusive economic zone (EEZ) from 2010 to 2020

Analysis of the Natuna Islands Conflict between Indonesia and China in the Perspective of International Law

This article aims to analyze the dispute between Indonesia and China regarding the Natuna Islands from an international law perspective. As a maritime country with many islands, Indonesia has abundant natural wealth in its territory. However, Indonesia and China's conflicting claims over the Natuna Islands have created tensions and disputes between the two countries. The dispute is related to the ownership and utilization of resources on Natuna Island which is in the Indonesian Exclusive Economic Zone. The impact of this dispute includes economic instability, divisions between countries, political losses, and social problems. In dealing with these impacts, it is necessary to carry out effective resolution efforts. Settlement of the Natuna islands dispute between Indonesia and China can be done through several strategic steps. First, regional border management is improved, economic activity is improved by exploring for oil in the Natuna Islands, then through an international legal approach, this article will review the relevant legal basis, legal arguments used by both parties, as well as possible settlement efforts.

Predicting the distribution and abundance of abandoned, lost or discarded fishing gear (ALDFG) in the deep sea of the Azores (North Atlantic)

Abandoned, lost, or discarded fishing gear (ALDFG), represents a significant percentage of the global plastic pollution, currently considered one of the major sources from sea-based activities. However, there is still limited understanding of the quantities of ALDFG present on the seafloor and their impacts. In this study, data on the presence of ALDFG was obtained from a large archive of seafloor video footage (351 dives) collected by different imaging platforms in the Azores region over 15 years (2006–2020). Most ALDFG items observed in the images relate to the local bottom longline fishery operating in the region, and include longlines but also anchors, weights, cables and buoys. A generalized additive mixed model (GAMM) was used to predict the distribution and abundance of ALDFG over the seafloor within the limits of the Azores Exclusive Economic Zone (EEZ) using a suite of environmental and anthropogenic variables. We estimated an average of 113 ± 310 items km−2 (597 ± 756 per km−2 above 1000 m depth), which could imply that over 20 million ALDFG items are present on the deep seafloor of the Azores EEZ. The resulting model identified potential hotspots of ALDFG along the seabed, some of them located over sensitive benthic habitats, such as specific seamounts. In addition, the interactions between ALDFG and benthic organisms were also analysed. Numerous entanglements were observed with several species of large anthozoans and sponges. The use of predictive distribution modelling for ALDFG should be regarded as a useful tool to support ecosystem-based management, which can provide indirect information about fishing pressure and allow the identification of potential high-risk areas. Additional knowledge about the sources, amounts, fates and impacts of ALDFG will be key to address the global issue of plastic pollution and the effects of fishing on marine ecosystems.

Movement and vertical habitat use of yellowfin tuna Thunnus albacares in a vertically compressed habitat: the Galápagos Marine Reserve.

Tropical pelagic predators are exploited by fisheries and their movements are influenced by factors including prey availability, temperature, and dissolved oxygen levels. As the biophysical parameters vary greatly within the range of circumtropical species, local studies are needed to define those species' habitat preference and model possible behavioral responses under different climate change scenarios. Here, we tagged yellowfin tuna Thunnus albacares in the Galápagos Marine Reserve and tracked the horizontal and vertical movements of eight individuals for 4-97 days. The tuna traveled a mean of 13.6 km day-1 horizontally and dispersed throughout the archipelago and in offshore waters inside the Galápagos Marine Reserve and in the surrounding Ecuadorian exclusive economic zone. Vertically, they traveled a mean of 2 km day-1 , although high-resolution data from a recovered tag suggested that transmitted data underestimated their vertical movement by a factor of 5.5. The tracked yellowfin tuna spent most of their time near the surface, with an overall mean swimming depth of 24.3 ± 46.6 m, and stayed shallower at night (11.1 ± 16.3 m) than during the day ( 37.7 ± 60.9 m), but on occasion dived to cold, oxygen-poor waters below 200 m. Deep dives were commonly made during the day with a mean recovery period of 51 min between exposures to modeled oxygen-limiting conditions <1.5 mL L-1 , presumably to re-oxygenate. The depth and frequency of dives were likely limited by dissolved oxygen levels, as oxygen-depleted conditions reach shallow depths in this region. The main habitat of tracked yellowfin tunas was in the shallow mixed layer, which may leave them vulnerable to fishing. Vertical expansion of low-oxygen waters under future climate change scenarios may further compress their habitat, increasing their vulnerability to surface fishing gear.

Integrating survey and observer data improves the predictions of New Zealand spatio-temporal models

AbstractIn many situations, species distribution models need to make use of multiple data sources to address their objectives. We developed a spatio-temporal modelling framework that integrates research survey data and data collected by observers onboard fishing vessels while accounting for physical barriers (islands, convoluted coastlines). We demonstrated our framework for two bycatch species in New Zealand deepwater fisheries: spiny dogfish (Squalus acanthias) and javelinfish (Lepidorhynchus denticulatus). Results indicated that employing observer-only data or integrated data is necessary to map fish biomass at the scale of the New Zealand exclusive economic zone, and to interpolate local biomass indices (e.g., for the east coast of the South Island) in years with no survey but available observer data. Results also showed that, if enough survey data are available, fisheries analysts should: (1) develop both an integrated model and a model relying on survey-only data; and (2) for a given geographic area, ultimately choose the index produced with integrated data or the index produced with survey-only data based on the reliability of the interannual variability of the index. We also conducted a simulation experiment, which indicated that the predictions of our spatio-temporal models are virtually insensitive to the consideration of physical barriers.

Improving Marine Megafauna Knowledge with eDNA: A French Story

In the current context of large-scale biodiversity loss (Díaz et al. 2019), it is urgent to carry out biodiversity inventories in order to investigate spatial and temporal variations. Among the available methods, environmental DNA (eDNA) (Taberlet et al. 2018) combined with molecular metabarcoding (Valentini et al. 2009) bring new insights in drafting inventories of taxa present in an environment. Approaches based on eDNA facilitate the study of remote ecosystems and the detection of rare, cryptic or invasive species in a non-invasive way (Bohmann et al. 2014). In the marine realm, the study of mobile fauna, including mammals particularly, can greatly benefit from these new techniques. Here, we present a case study carried out in the northeast and northwest Atlantic, within the boundaries of marine protected areas. The Iroise Natural Marine Park*1 was the first French marine natural park created in France in 2007 (Fig. 1). The first campaign in the Iroise Natural Marine Park successfully detected several species of cetacean (e.g., Lagenorhynchus albirostris, Lagenorhynchus obliquidens) and four species of elasmobranchs (e.g., Scyliorhinus canicula, Torpedo marmorata, Raja undulata and Mustelus asterias). This study was extended to the Martinique Natural Marine Park*2, where similar analyses identified three cetacean species (Stenella attenuata, Lagenodelphis hosei and Tursiops truncatus) and 193 teleost taxa (Riou 2022), representing more than half of the species expected in Martinique. The analyses carried out in Martinique highlighted several remarkable sites for fish biodiversity. In Guadeloupe, in the heart of the Agoa Marine Mammals Sanctuary*3 (corresponding to the French Antilles exclusive economic zone), the taxonomic composition of different eDNA samples made in 2021 and 2022 was compared. The samples were analyzed using different primer sets, specific to vertebrates, teleosts and mammals. Comparison of the results obtained with vertebrate-specific primers and those specific to teleosts showed complementary results. For cetaceans, the analyses distinguished ten distinct cetacean taxonomic units and at least 3 distinct species from four samples. In addition, the eDNA samples were used to discriminate between the two recently recognised bottlenose dolphin ecotypes, based on the observation of a fixed nucleotide difference on the barcode targeted by the mammal-specific primers. New primers are currently being developed to make it easier to distinguish species of Delphinidae, which are still complex to identify. Environmental DNA and metabarcoding offer new possibilities for the inventories of marine megafauna and support adequate conservation decision-making processes. It is a major step towards better monitoring of marine mammal populations of the Atlantic Ocean. Moreover, our datasets will be freely available through open platforms following the FAIR (Findable, Accessible, Interoperable, and Reusable) principles.

POTENTIAL, CHALLENGES, AND PROSPECTS FOR PAKISTAN'S BLUE ECONOMY

The value of water and oceans in fostering inhabitation and facilitating trade and economic connectivity is immense. Sea-trade has historically played a crucial role in building a state's economic power. Pakistan, with over 1000 km of coastline and an extended Exclusive Economic Zone covering 290,000 sq.km, possesses abundant marine, fisheries, mineral, and energy resources that can generate significant revenues. Additionally, Pakistan's geo-oceanic position offers vast opportunities for sea-based activities like transportation, tourism, shipbuilding, port facilities, and renewable energy. This paper highlights the challenges and prospects of Pakistan's Blue Economy, providing policy recommendations for its development.

Can seaweeds feed the world? Modelling world offshore seaweed production potential

Pressure on the terrestrial ecosystems is large and big concerns exist regarding whether a growing world population can be fed from the land. Little is known about if and how much these concerns could be alleviated by harvesting more from the oceans. We modelled the biophysical production potential of seaweeds, and their current and possible future contribution to world food supply. We estimate seaweeds currently provide up to 0.13% of global food energy supply. Seaweed production is increasing more rapidly than terrestrial production. At current rates of increase we estimate seaweed energy contribution of 0.25% in 2050. Production potential of seaweeds could contribute up to 2 to 14% of global food supply if farming 1% of the modelled suitable space within the Exclusive Economic Zone. We show this large potential contribution to world food supply will only be achieved with unprecedented increases in seaweed production, while offshore seaweed cultivation is still in its infancy. The study shows large uncertainties that warrant further research. Modelling shows vast areas of world oceans are unsuitable because of being too far out of shore, having too low nutrient concentrations or having too high waves. Only 2–9% of world oceans and 6–25% of the Exclusive Economic Zone (EEZ) was shown to be suitable for seaweed production. Identifying suitable sites for offshore seaweed cultivation is therefore important. Site suitability maps reported for the 3 model species can be useful for private companies and policy makers expanding seaweed in new high potential production areas around the world.

Rising snow line: Ocean acidification and the submergence of seafloor geomorphic features beneath a rising carbonate compensation depth

Due to burning of fossil fuels, carbon dioxide is being absorbed by the ocean where its chemical conversion to carbonic acid has already caused the surface ocean to become more acidic than it has been for at least the last 2 million years. Global ocean modeling suggests that the carbonate compensation depth (CCD) has already risen by nearly 100 m on average since pre-industrial times and will likely rise further by several hundred meters more this century. Potentially millions of square kilometres of ocean floor will undergo a rapid transition in terms of the overlying water chemistry whereby calcareous sediment will become unstable causing the carbonate “snow line” to rise.We carried out a spatial analysis of seafloor geomorphology to assess the area newly submerged below the rising CCD. We found that shoaling of the CCD since the industrial revolution has submerged 12,432,096 km2 of ocean floor (3.60% of total ocean area) below the CCD. Further hypothetical shoaling of the CCD by 100 m increments illustrated that the surface area of seafloor submerged below the CCD has risen by 14% with 300 m of shoaling, such that 51% of the ocean area will be below the CCD. All categories of geomorphic feature mapped in one global database intersect the lysocline and will be (or already are) submerged below the CCD with much regional variation since the rise in CCD depth during the last 150 years varies significantly between different ocean regions. For seamounts, the highest percentages of increase in area submerged below the CCD occurred in the Southern Indian Ocean and the South West Atlantic regions (6.3% and 5.9%, respectively). For submarine canyons we found the South West Atlantic increased from 3.9% in pre-industrial times to 8.0% at the present time, the highest percentage of canyons found below the CCD in any ocean region.We also carried out a relative risk assessment for future submergence of ocean floor below the CCD in 17 ocean regions. In our assessment we assumed that the change in CCD from pre-industrial times to the present is an indicator of the likelihood and the change in percentage of seafloor submerged below the CCD due to a hypothetical 300 m rise in the CCD is an indicator of the consequences. We found that the western equatorial Atlantic is at high risk and 9 other Ocean Regions are at moderate risk. Overall, geomorphic features in the Atlantic Ocean and southern Indian Ocean are at greater risk of impact from a rising CCD than Pacific and other Indian Ocean regions.A separate analysis of the Arctic Ocean points to the possible submergence of glacial troughs incised on the continental shelf within a mid-depth (400–800 m) acidified water mass. We also found that the area of national Exclusive Economic Zones submerged below the rising CCD exhibits extreme variability; with 300 m of CCD shoaling we found a > 12% increase in area submerged below the CCD for 23 national EEZs, whereas there was virtually no change for other countries.

An investigation on the use algae-based material for the production of reusable bioplastic bags: A Mauritian case study

The Government of Mauritius has come up with new regulations in an attempt to ban the use of petroleum based plastics bags so as to protect the environment. Hence it is important to find substitute materials to achieve this goal set by the government. Interestingly though, Mauritius being an island with a large Exclusive Economic Zone (EEZ), there is an abundancy of seaweeds, which is an interesting avenue to explore. The unexploited seaweed in the waters surrounding Mauritius remains a remarkably potential raw material for the manufacture of an alternative to petro-plastics, especially polypropylene non-woven bags, in the form of reusable and fully biodegradable bioplastic bags. This research attempts to investigate the use of algae, mainly Gracilaria Salicornia and Ulva lactuca as a potential; raw material for the production of reusable bioplastic bags through Taguchi optimisation method for the culling of optimum constituent wt.%. For the preparation of the biofilm to be solution casted, cassava starch, algae powder, glycerol and acetic acid were selected as controllable factors. The Taguchi L9 orthogonal array experimental design plan was considered for carrying out the experiments. The responses analysed were the tensile strength, water absorption, biodegradation and water vapour permeability. A maximum tensile strength and degradation of 7.325 MPa and 91.32% respectively were achieved from Taguchi optimal conditions. A maximum water absorption and minimum water vapour permeability of 60.3 % and 3.0181 g/h.m2 respectively were evaluated from the experiments. Contribution of factors to the responses were determined through analysis of variance. Furthermore, regression models and contour plots were developed for predicting the best combination which was determined to be 8 % (w/v) starch, 3 % (w/v) algae, 1 % (w/v) glycerol and 8 % (w/v) acetic. An Ulva lactuca blend was experimented to act as substitute for cassava starch, achieving a tensile strength and water absorption of 3.578 MPa and 175.0 % respectively. Compared to other materials, used for bag production, available on the market, the mechanical properties of the developed algae-based material showed its potential as a replacement with some having much higher tensile strength confirming its successful usage.

Policies for potentially inundated island nations for the retention of marine resources and rights of associated under-water features and exclusive economic zones

Sea level rise is one of the primary drivers of global ecosystem change, with significant and far-reaching consequences for the social and natural environments of islands. The emphasis on maintaining marine resources, and the rights associated with underwater features and exclusive economic zones, has notably intensified for Small Island Developing States (SIDSs). Despite these states possessing legally secured rights to maritime zones, their inadequate capacity for marine governance could render them susceptible to rampant illegal, unreported, and unregulated (IUU) fishing, as well as the tangible loss of these resources. Consequently, such approaches thus lack effectiveness to promote SIDSs’ adaptation to climate targets and the retention of marine resources. Therefore, this paper uses the coevolutionary framework to analyse the synergies among policies in SIDSs, from the perspective of institutional diversity. It summarises 107 policies into the categories of engineering, economy, cooperation, and education. Based on the results of this categorisation, the challenges and key trends underlying the implementation of such policies in SIDSs are explored. Two corresponding recommendations are developed, which include building island resilience based on acknowledging the diversity of environmental and social issues among SIDSs and promoting “learning-by-doing” in those SIDSs.