No-take Zones Research Articles

Illegal fishing and compliance management in marine protected areas: a situational approach

Protected Areas (PAs) are spatially representative management tools that impose various levels of protection for conservation purposes. As spatially regulated places, ensuring compliance with the rules represents a key element of effective management and positive conservation outcomes. Wildlife crime, and in particular poaching, is a serious global problem that undermines the success of PAs. This study applies a socio-ecological approach to understanding the opportunity structure of illegal recreational fishing (poaching) in no-take zones in Australia’s Great Barrier Reef Marine Park. We use Boosted Regression Trees to predict the spatio-temporal distribution of poaching risk within no-take Marine National Park zones. The results show that five risk factors account for nearly three quarters (73.6%) of the relative importance for poaching in no-take zones and that temporally varying conditions influence risk across space. We discuss these findings through the theoretical lens of Environmental Criminology and suggest that law enforcement strategies focus on reducing the negative outcomes associated with poaching by limiting the opportunity of would-be offenders to undertake illegal activity.

Illegal fishing and compliance management in marine protected areas: a situational approach

Protected Areas (PAs) are spatially representative management tools that impose various levels of protection for conservation purposes. As spatially regulated places, ensuring compliance with the rules represents a key element of effective management and positive conservation outcomes. Wildlife crime, and in particular poaching, is a serious global problem that undermines the success of PAs. This study applies a socio-ecological approach to understanding the opportunity structure of illegal recreational fishing (poaching) in no-take zones in Australia’s Great Barrier Reef Marine Park. We use Boosted Regression Trees to predict the spatio-temporal distribution of poaching risk within no-take Marine National Park zones. The results show that five risk factors account for nearly three quarters (73.6%) of the relative importance for poaching in no-take zones and that temporally varying conditions influence risk across space. We discuss these findings through the theoretical lens of Environmental Criminology and suggest that law enforcement strategies focus on reducing the negative outcomes associated with poaching by limiting the opportunity of would-be offenders to undertake illegal activity.

Movement patterns and growth rate of cavebass Dinoperca petersi (Pisces: Dinopercidae) in the iSimangaliso Marine Protected Area, South Africa

Dinoperca petersi is a relatively common fish species caught in the line-fishery in KwaZulu-Natal (KZN), South Africa. Yet, little is known about the biology and ecology of this species. Movement patterns and growth rate of this species were studied based on data obtained from a long-term tag-recapture study conducted in the iSimangaliso Marine Protected Area in northern KZN between 2001-2019. Results showed that D. petersi is a highly resident species with a linear home-range size of 290-405 m. While most fish showed high site fidelity, 8.8 % of the tagged fish showed wider ranging movements of 2.4-90 km. However, only 5 fish showed movements out of no-take zones into adjacent exploited areas, suggesting limited adult spillover. Growth rate of tagged fish was found to be reasonably slow compared to other sympatric predatory reef fish with an average growth rate of 61.76 mm y–1 for smaller fish (gα = 300) and 9.58 mm y–1 for larger fish (gβ = 550). Based on these life history characteristics, options for the future conservation and management of this species are discussed.

Single-Species Co-management Improves Fish Assemblage Structure and Composition in a Tropical River

Co-management is increasingly recognized as an effective model for managing fisheries, but little information exists on whether co-management can produce effects in species other than the target species. Fishery co-management in the tropics, where fish diversity is high and fish catches tend to be multispecies, is prone to produce assemblage-wide effects via alterations in the food web and changes in the overall capture of non-target species. Here, we assessed the effects of co-management for the species Arapaima sp. in relation to the structure and composition of the overall fish assemblage in floodplain lakes of the central Amazon Basin. These floodplain lakes are managed under a system of zoning of fishing activities. We used data from surveys of six floodplain lakes, including two lakes of each of three categories (lakes where fishing is prohibited, limited-access lakes, and open fishing lakes). The surveys were carried out before and after implementation of co-management, through gillnet fishing. The study area was the lower Solimões River, in the Amazon Basin, Brazil. Statistical models showed significant changes in the composition and structure of the fish assemblages after the implementation of the co-management, regardless of the zoning category. Through regulation of gear use and fishing practices, co-management allowed the colonization of species that had not been present before, which lead to higher richness and consequently increased fish sizes, abundance and biomass. Species of sedentary habits, migrants of short and medium distances, with commercial importance benefited the most from co-management. In the results presented in temporal scale, it was possible to observe a potential spillover effect being provided by the lakes where fishing is prohibited (no-take zones) and those of limited access that benefited those open to fishing. Thus, co-management had positive effects in the structure and composition of fish assemblages in all lakes, regardless of zoning category.

The Marxan model for determining no-catch zones based on conservation targets in the north-eastern region of Simeulue District

Aceh Governor’s Decree Number 523/1297/2018 concerning the Determination of Reserve Reservation for Aceh Waters allows Pinang, Siumat and Simanaha Islands (PISISI) in the northeast region of Simeulue Island to become one of the conservation zones that have a no-take zone. Therefore, it is necessary to have a scientific analysis of the management and zoning plan especially in determining the location of the core zone (no-take zone). Determination of the core zone is the most important part in planning to protect coastal areas as a form of sustainable management of fish resources and the environment. The purpose of this study is to determine the location of no-take zones based on conservation targets that have high biodiversity values in the PISISI area of Simeulue Island. Therefore, the Marxan model is used which is a design plan for the conservation zoning design. The analysis shows that there are eight areas that can be used as a no-catch area based on coastal habitats, biodiversity, and high conservation value. The model results indicate that no-take zones will be able to protect 80% of conservation targets. Simulation results also show that the area of the no-take zone is around 2,283.89 ha.

Gonad maturity and gonadal somatic index of blue swimming crab Portunus pelagicus harvested from Spermonde Archipelago, South Sulawesi, Indonesia

Reproductive biology is one of the biological aspects that needed to formulate responsible management of blue swimming crab (BSC). The crab is one of the commercial fisheries commodities in South Sulawesi, Indonesia. Presently no information on the reproductive biology of this crab from Spermonde Archipelago, Sout Sulawesi. Therefore, the study aimed to analyze and compare gonad maturity stage(GMS)andgonadalsomaticindex(GSI)oftheBSCcaughtonthreeecosystemsnamelycoralreef,seagrass,andmangrovein Salemo Island, Spermonde Archipelago. GMS and GSI were analyzed descriptively for five months from March to July 2015. Results indicate there was a difference in GMS of the BSC caught in mangroves, seagrass, and coral reef. Generally, mangrove was dominated by immature BSC with GMS I and GMS II, while the BSC caught in the seagrass and coral reef BSC were dominantly mature and spawn GMS III, IV, and V. GSI BSC caught in mangrove ecosystem are smaller than GSI BSC caught in seagrass and coral reef ecosystems. Seagrass and coral reef ecosystems suitable for development no-take zone of the BSC.

European hake (Merluccius merluccius, Linnaeus 1758) spillover analysis using VMS and landings data in a no-take zone in the northern Catalan coast (NW Mediterranean)

The analysis of fish spillover from marine protected areas (MPA) is often based on data collected after the implementation of protection. In the present study we used a methodology based on the combination of Vessel Monitoring System (VMS) and landings data before and after the establishment of protection for spillover analysis. We defined areas of similar size to the protected zone in order to compare them over time. In addition to the no-take zone effectiveness, using this methodology, we were also able to analyze the spatiotemporal behavior of the hake population. Our results on the hake distribution were consistent with those of previous studies. The juveniles were concentrated on the continental shelf (0 - 200 m), whereas the adults were found over the shelf and the slope (300 - 500 m). We found evidence suggesting a positive spillover effect for the juveniles on the continental shelf, enhancing its fishing yields. The analysis of longer time series on the performance of the protected area combined with field sampling inside the no-take zone would lead us to confirm effective spillover effect contributing to fisheries’ long-term sustainability in this zone.

Changes in prey fields increase the potential for spatial overlap between gentoo penguins and a krill fishery within a marine protected area

AbstractAIMManagement of competition with predators is an important consideration for fisheries, particularly within marine protected areas (MPAs) where conservation is a primary objective. We aimed to test whether static no‐take zones within a large, sustainable‐use MPA prevented overlap between gentoo penguins and a krill fishery during two winters with contrasting prey fields.LOCATIONSouth Georgia, Southwest Atlantic Ocean.METHODWe used satellite tracking (N = 16, June–September 2018) to describe gentoo penguin movements and distribution and quantified their overlap with the MPA’s no‐take zone (NTZ) and the krill fishing grounds. DNA metabarcoding of scats (N = 220, April–September 2018) was used to quantify diet.RESULTSWhen krill were at moderate densities and evenly distributed in 2001, gentoo penguins would have spent all of their time within the 12 NM NTZ, but when availability was low in 2018, they spent 46.3% of their time outside the NTZ and 9.6% within the krill fishing grounds. The extension of the NTZ to 30 km in response to this finding would have produced a 14.9% increase in protection for penguins and displaced 4% of fishery hauls. Gentoo penguin diet comprised 25.8% krill, which is lower than in the late 1980s but more than in 2009.MAIN CONCLUSIONSGentoo penguins extend their foraging range when krill is scarce, which increases the potential for spatial overlap with the krill fishery during periods of nutritional stress. Current regulations allow for expansion of both extent and catches by the krill fishery and, should this occur, gentoo penguins may face heightened risks from competition. A dynamic ocean management framework, that extends closed areas in response to near real‐time data on penguin movements and krill density estimates, may reduce the potential for competition in this sustainable‐use MPA while allowing a profitable krill fishery.

Overexploitation and behavioral changes of the largest South Atlantic parrotfish (Scarus trispinosus): Evidence from fishers' knowledge

Assessing species conservation status and population trends is challenging especially on low and low-middle income countries mostly due to high costs. Therefore, long-term information about species gained through local ecological knowledge, can reveal threatening and overexploitation scenarios aiming to generate information for extinction risk reduction and conservation priority targets. The greenbeak parrotfish, Scarus trispinosus, is an endemic and endangered Brazilian species with records of local extinction along its distribution, however limited data on its fisheries is available. We investigated fisher's local ecological knowledge on S. trispinosus on the largest Brazilian coastal multiple-use marine protected area. We interviewed small-scale fishers regarding catches to verify temporal changes in abundance and body size. Additionally, we verified if S. trispinosus flight initiation distance, proxy of tolerance from fisher's approximation has changed over different fishers' generations. Our results revealed that the number of individuals decreased 64% over time from 1980s to 2010s with a constant decrease through time. The weight of the largest individual ever caught also decreased 67% over time. Flight initiation distance, when fishers firstly engaged on fishing activity, was smaller for more experienced fishers. Implementation of small-scale co-management strategies, together with creation and enforcement of no-take zones are essential to safeguard the remaining populations and allow the greenbeak parrotfish recovery. Our study demonstrated that local ecological knowledge on species population and behavioral changes can be used as an alternative and inexpensive approach for assessing impact on threatened species and could be applied on conservation strategies for several species and ecosystems worldwide.

Marine fishery dependence, poverty and inequality nexus along the coastal lowlands of Kenya

This paper examines the nexus between marine fishery dependence, poverty and inequality among households in coastal lowlands of Kenya, specifically, Kilifi County. Data for the study were collected from 384 randomly selected households through structured pretested questionnaires. The study used the multidimensional poverty methodology and multivalued treatment effect model to determine the marine fishery dependence of households, poverty, and inequality nexus. Findings from the study show that increasing ocean fishery dependence is associated with increased poverty and inequality among the dependent households. However, it is worth mentioning that other factors may as well affect poverty. Results also revealed that fishing was not a choice, but rather a necessity with approximately 71.3% of the dependent households reporting a lack of alternative livelihood options. More so, the dependent households that pursued diversification livelihood strategies had a lower deprivation score at 0.29 compared to 0.47 that engaged solely in fishing. Welfare policies such as the establishment of Beach Management Units (BMU), No Take Zones (NTZs), locally managed marine areas (LMMAs), and information networks have been put in place to promote the livelihoods of the fishing communities. However, their implementation has been ineffective leading to social exclusion and hence poverty traps among the poorest dependent households. The study, therefore, recommends strengthening existing governance options while putting a special focus on gear regulations.

Networking between marine protected areas help sustain fisheries

Marine protected areas called no-take zones – restricting human activities – are set to preserve marine ecosystems. But these same marine reserves could also help sustain fisheries. A new study reveals that a network of no-take zones provides a reliable source of offspring, which replenishes fish stocks and minimizes risk to ecosystems. - submission by Hugo B. Harrison

Setting the Context for Offshore Wind Development Effects on Fish and Fisheries

Changes to fisheries that result from offshore wind farm (OWF) installations may be considered good or bad depending on various stakeholders’ perspectives. OWFs can act as artificial reefs that may benefit secondary fish production, but such effects may also have ecological consequences. The fisheries exclusion effect that turns some OWFs into no-go areas, hence effectively no-take zones, could provide resource enhancements or redistribution. However, the displacement of fishing effort may have consequences to fisheries elsewhere. Changes in the sensory environment related to sound, as well as electromagnetic fields and physical alterations of current and wind wakes, may have as yet unknown impacts on fisheries resources. Understanding the interactions among effect type, OWF development phase, and spatiotemporal population dynamics of commercial and recreational species remains chal-lenging, exemplified by the commercial fishery lobster genus Homarus in European and North American waters. While knowledge of the interactions between resource species and OWFs is improving, there remain questions on the wider interaction between and consequences of OWFs and fisheries. Studies of this wider relevance should aim to improve understanding of the economic and societal impacts of OWFs linked to ecosystem services that support fisheries. Furthermore, assisting fisheries management and providing advice requires monitoring and survey data collection at appropriate spatiotemporal scales. This information will help to determine whether OWFs have any meaningful impact on regional fisheries, and increased investments will be needed to target scientifically appropriate monitoring of OWFs and fisheries, which is supported by better integrated policy and regulation.

Ecological traits, genetic diversity and regional distribution of the macroalga Treptacantha elegans along the Catalan coast (NW Mediterranean Sea)

The widespread decline of canopy-forming macroalgal assemblages has been documented in many regions during the last decades. This pattern is often followed by the replacement of structurally complex algal canopies by more simplified habitats (e.g., turfs or sea urchin barren grounds). Against all odds, the fucoid Treptacantha elegans, a large Mediterranean brown macroalga, broadened its depth range to deeper and exposed environments and displayed an unexpected range expansion along the northern coast of Catalonia over the last two decades. Here, we reconstruct the spread of T. elegans in time and space and unravel ecological and demographic traits such as population dynamics and genetic patterns to provide a comprehensive and integrated view of the current status and geographical expansion for this species. Fast-growing dynamics, early fertile maturity, and high turnover rate are the main competitive advantages that allow the exposed populations of T. elegans to colonize available substrata and maintain dense and patchy populations. We also provided evidence that the deeper and exposed populations of T. elegans constitute a single group across the Catalan coast, with little genetic differentiation among populations. This seems to support the hypothesis of a unique source of spread in the last decades from the Medes Islands No-Take Zone towards both southern and northern waters.

Being Isolated and Protected Is Better Than Just Being Isolated: A Case Study From the Alacranes Reef, Mexico

Isolated reefs suffered from overfishing to a lesser extent than coastal reefs systems. Nevertheless, the exploitation of coastal areas forced fishers to move offshore to compensate for their decreasing catches, helped by an overall increase in their technological capabilities. Thus, these once pristine isolated areas are under increasing threat and should be considered a protection priority. Here, we compared the fish and epibenthic community of two isolated coral reefs in the southern Gulf of Mexico: one is the Alacranes reefs a Marine Protected Area (MPA) with two No-Take Zones (NTZs) and the other is Bajos del Norte an Open Area (OA). Alacranes reef is ~135 km off the northern coast of the Yucatan Peninsula while Bajos del Norte ~160 km. Our results show that despite being isolated, the OA reefs never reach the same biomass levels of MPA or NTZ reefs which in some cases exceeded 1 ton/ha. Furthermore, 70% of the reefs within NTZ and MPA had a large predatory fish (e.g. sharks, jackfish, groupers) biomass relative contribution larger than 25%, while only two reefs in the OA had a relative piscivore contribution of more than 25%. Large predatory fish have a larger contribution to overall biomass within NTZs than MPAs reefs, even at low biomass values, suggesting that NTZ is more effective in protecting large predators. NTZ and MPA reefs also showed from 5 to 10% higher coral cover than OA which had a higher erect algae cover (~22.9%). Indicating that the disruption of the trophic pyramid caused by the fishing pressure in OA reefs is reflecting on the trophic cascades controlling the benthic communities balance. These isolated areas represent the last pillars of natural diversity and are under such an increasing anthropogenic pressure that just being isolated is not enough anymore to guarantee a safe zone from detrimental activities like overfishing. Immediate establishment of protective NTZ is needed to maintain the role they play as a natural wilderness capital.

Evaluating Antarctic marine protected area scenarios using a dynamic food web model

Marine protected areas, especially when they are or include no-take zones, can support conservation objectives by creating an area where marine organisms are protected from human disturbances, particularly fishing. The coast of the Antarctic continent is the only habitat of the iconic Adélie penguin, whose main diet is Antarctic krill. Current threats to Adélie Penguins, other Antarctic krill predators and Antarctic krill itself include sea-ice loss as a result of climate change and krill fishing. We use a spatially and temporally dynamic food web model of the region surrounding the Western Antarctic Peninsula to evaluate the potential impacts of various marine protected area scenarios in the context of climate change. We examine the effects of sustained sea-ice loss on krill and seven monitored krill predators. We evaluate four marine protected area scenarios given two scenarios that describe future changes in sea ice and three scenarios that describe future changes in krill fishing effort. Our results indicate that establishing no-take zones where krill might aggregate in the future and where some krill predators forage could positively affect biomass accumulation of krill and the predators. No-take zones may be particularly important for enhancing the resilience of species that have recently experienced population decline and ensuring positive outcomes from establishing a marine protected area in the region. Our simulations suggest that establishing protected areas in the right locations can play an important role in mitigating the negative effects of climate change on iconic species that many people want to conserve.

Protection Efforts of Lutjanus bohar (The Two-Spot Red Snapper) Spawning Area in Hoga Island Waters, Kaledupa-Wakatobi National Park

A spawning area of Lutjanus bohar, a marine fish of high economic value, is one of the eight important resources of Wakatobi and also a critical habitat in the waters of Hoga Island. For protecting the area, Wakatobi National Park has stated the area as a tourism zone (no-take zone). This research was conducted to evaluate progress toward spawning-area protection by examine number of individuals, length size of fish, and trespassing cases that occurred in the spawning area. Research was carried out in 2018-2019. Number of individuals and size of fish were collected by referring to the monitoring guidelines for the Spawning Aggregation Site (SPAGs), and observations with an Underwater Visual Census. Trespassing case data were collected by interview key persons. Descriptive analysis was used to describe progress toward spawning-area protection. The results indicate that the protection effort of spawning area has a positive impact in increasing number of individuals and length of Lutjanus bohar. However, number of trespassing cases in the waters of Hoga Island still shows an increase. Fishing activities are the most trespassing cases occurred in the spawning area. This approach should be implemented to evaluate the progress towards protection efforts, besides increasing the number of patrols and socialization with fishermen to increase their awareness.

Vulnerability and Decision-Making in Multispecies Fisheries: A Risk Assessment of Bacalao (Mycteroperca olfax) and Related Species in the Galapagos’ Handline Fishery

Marine fish populations can be vulnerable to overfishing, as a response of their life history, ecology, and socio-economic aspects. Vulnerability assessments, in this regard, can be used to support fisheries decision-making by aiding species prioritization. Assessments like Productivity–Susceptibility Analyses are well suited for multispecies fisheries, with low gear selectivity and insufficient fishery-independent and dependent data. Using this method, we assessed local vulnerability of the Galapagos grouper (‘bacalao’; Mycteroperca olfax) and compared it with other phylogenetically-related species caught in the Galapagos’ handline-fishery. Bacalao is an overfished regionally endemic fish species, characterized by low resilience, high market and cultural value and high spatial overlap with the fishery. Our results suggested that bacalao is a species of high management priority, requiring urgent measures to prevent fisheries’ collapse. In addition, if current fishing pressure persists, other related species may become threatened in the near future. We also evaluated different management scenarios using this approach. Results suggested that the inclusion of additional no-take zones in the marine reserve, comprising key nursery habitats (such as mangroves) and spawning aggregation sites, would be necessary to reduce species vulnerability and to benefit other related species. Improving enforcement and fishers’ compliance are essential to guarantee the effectiveness of these measures.

Effects of depth on reef fish flight initiation distance: implications of deeper reefs conservation

A reduced susceptibility for local and global impacts has been assigned for deeper reefs compared to historically degraded shallow reefs. Yet, few studies have attempted to analyze the influence of depth on reef fish escape behavior across distinct size classes. By using behavioral response as a measure for prey wariness, the present study analyzed flight initiation distance (FID) for three fishery target and one non-target reef fish species on shallow and deeper reefs in South Atlantic Ocean (Multiple use MPA Costa dos Corais, Pernambuco State). We hypothesized that fish on shallow reefs would have higher FID and detect the human approach sooner and flee at a large distance than individuals in deeper reefs, which would have a late detection, allowing a closer approach. During our field experiment, flight initiation distances average was higher at shallow reefs for three analyzed species, yet each species had specific responses according to individual size classes. For two fishery target species E. adscensionis and C. fulva, two intermediate size classes presented higher flight distances at shallow than deeper reefs. However, S. axillare a target parrotfish, demonstrated an unexpected trend with higher FID on deeper reefs for smaller size classes. Interestingly, the non-target species, have also shown differences on wariness across the two analyzed size classes, with higher FID on shallow than deeper reefs. Our results suggest that fish on shallow reefs would detect the human approach sooner and flee at a large distance than individuals in deeper reefs; however, fish response to human presence according to depth is size classes and species dependent. We emphasis the important of no-take zones and the establishment of new marine protected areas on both shallow and deeper reefs in Brazilian waters and elsewhere in order to maintain the integrity of reef fish behavior and consequently ecosystems functioning.

Reproductive Aspects of Banana Prawn (Fenneropenaeus Merguiensis) For Recommendations of The South Sorong MPA Zone

Reproduction aspects of banana prawn were important in determining of the fisheries management. These results can indicate the condition of fisheries that are or will be managed. Banana prawn was one of the main commodities in South Sorong fisheries. This study aims to estimate some of the reproductive aspects of Fenneropenaeus merguiensis as part of a management measure to determining the zone to be a no-take zone area in the prospective area of South Sorong MPAs. The data analyzed were from data collecting from January to December 2018 in three sampling sites in South Sorong, among others Inanwatan, Bakoi, and Konda with the results of 5,009 carapace length samples, 4,589 including sex observation and 3,621 including banana prawn GMS observations. Data analysis performed by analyzing the distribution of carapace length frequency, sex ratio, length-weight relationship, length at first maturity (Lm50), and length at first captured (Lc50). The results of this analysis showed that the ratio between male and female gender was not balanced, with male gender to be less with a ratio of 0.4: 1.4 overall in NTZ 2 and 3. Comparison of Lc and Lm in NTZ 2 and NTZ 3 were respectively Lc Lm. More fishing pressure will have implications to reduce the average size of banana prawn caught. Overall, NTZ 3 had relatively more stable conditions compared to NTZ 2.

Residency and dispersal of three sportfish species from a coastal marine reserve: Insights from a regional-scale acoustic telemetry network

Understanding the movements of adult fish around marine reserves is central to evaluating the importance of these areas to conservation but is difficult to quantify in many coastal settings. We used a 300 km long passive acoustic telemetry network to measure site fidelity and dispersal distances of adult red drum (Sciaenops ocellatus), black drum (Pogonias cromis), and spotted seatrout (Cynoscion nebulosus) tagged within two estuarine no-take zones at Kennedy Space Center, Florida, USA. Seventy-eight tagged fish were tracked an average of 549 days with some individuals followed for over four years. Fish spent most of their total time at liberty inside no-take zones with a mean residency of 125–178 consecutive days after release, and 67%–95% of their total time, depending on species. Sixty-four individuals (82%) also utilized adjacent public waters, dispersing up to 650 km, although dispersal rates averaged less than 0.10 km day−1 for all three species. Red drum and black drum movements across reserve boundaries were clearly bi-directional with individuals averaging 4 and 30 excursions per year, respectively, into fished areas. Both species spent more time outside reserve boundaries during their reproductive periods, suggesting that these no-take zones protect individuals that subsequently spawn over a wider geographic area. Our findings demonstrate that coastal marine reserves have the potential to provide substantial protection for highly mobile non-reef fishes. They further suggest that reserves designed to safeguard fish during non-reproductive periods may be most practical for estuarine species whose home ranges increase during spawning seasons.