Enhancing reef fish diversity using artificial reef-building: A case study of coral reef rehabilitation on Nyamuk Island, Anambas Islands

CCMRS-IPB conducted coral reef rehabilitation at damaged coral reefs around Nyamuk Island. Those artificial reef buildings for rehabilitation gave shelter spaces for reef fish. This research aims to calculate the effect of coral reef-building, which enhances rugosity to the reef fish diversity around the rehabilitation sites. The study was conducted on Nyamuk Island in the Anambas Islands. Reef fish were sampled annually from 2014 to 2019 using the underwater visual census. The Diversity index and non-Metric Multidimensional Scaling were built to discover reef fish diversity, and reef fish species were affected the most. Yearly data shows an escalation number of reef fish abundance and richness at the end of 2019. The major reef fish group is found to have constant diversity throughout the year compared to other functional groups. The target reef fish group came to this rehabilitation ecosystem primarily attracted by nourishment availability. There is a shift in the reef fish diversity from the early year to the project end. Generally, major reef fish groups will be refuged first around the rehabilitation sites, especially territorial types. Target fish groups from herbivorous and carnivorous types will mostly come along after their food availability and location to get around.

The coral reef health at surrounding blue swimming crab fishery sites in Mandangin Island, East Java, Indonesia

Blue swimming crab fishery activities very often do not put into account the environmental condition. Coral reef, as one of the blue swimming crab habitats, can be affected by these activities. This study aims to determine the effect of blue swimming crab fisheries on coral health in Mandangin Island, East Java, Indonesia. Data collection points are determined based on the results of interviews by participatory mapping. Water quality data includes visibility, temperature, salinity, pH, DO, current velocity. Collecting coral reef data were using Line Intercept Transect (LIT), while for reef fish Underwater Visual Census (UVC) were used. The coral health index was determined based on the relevance between benthic components and fish components. The average of Mandangin Island’s water quality is in accordance with the quality standards of the Indonesian Minister of Environment Decree No.51 of 2004. Hard coral cover and fish biomass are classified as low, but the value of resilience is high. The coral reef health index value on Mandangin Island is 3.

Reef fish community on Sabira Island, Kepulauan Seribu Regency, DKI Jakarta

Sabira Island is an island close to Jakarta Province but still has good water conditions and a coral reef ecosystem with a high level of diversity. The condition of the coral reef ecosystem affects the community structure of the reef fish there. This study aims to determine the community structure of the reef fish on Sabira Island. The research was conducted in August 2019 on Sabira Island, Kepulauan Seribu Regency, DKI Jakarta Province. Observations of reef fish were carried out using the Underwater Visual Census method at four observation stations. There were 47 species of reef fish found on Sabira Island from 12 families. The total reef fish found were 1315 individuals, consisting of 79 indicator fish, 417 individual target fish, and 819 major fish. The highest diversity index value on Sabira Island was found at the South Station, with a diversity index value of 2.39. Based on the community structure index at the four observation stations, the reef fish community’s condition on Sabira Island is still good ranging from unstable to stable condition with moderate diversity and low dominance index values.

The condition of reef fish (family Chaetodontidae) in Krueng Raya and Ujong Pancu waters, Aceh Besar District

This study aims to determine the condition of reef fish of the Chaetodontidae family in Krueng Raya and Ujong Pancu waters, Aceh Besar District. The study was conducted in October 2019, where six observation locations were representing the two regions. Fish observations were carried out using the Underwater Visual Census (UVC) method. The results of the study found four genera of Chaetodontidae fish consisting of 21 species. Benteng Inong Balee Station is the location with the highest number of individuals and species of Chaetodontidae fish, 38 individuals belonging to 11 species. On the other hand, Lhok Mee Station is the location with the least number of individuals and species of Chaetodontidae fish found, only 13 individuals belonging to 6 species. The highest abundance of Chaetodontidae fish was found at Ahmad Rhang Mayang Station (521.11 ind/ha). Meanwhile, the least abundance of Chaetodontidae fish was found at Lhok Mee Station, ( 115.38 ind/ha). The number of species, Krueng Raya waters have a higher number of Chaetodontidae fish species than Ujong Pancu waters. On the other hand, the abundance value Ujong Pancu waters have a higher average abundance value of Chaetodontidae fish than Krueng Raya waters. Overall, based on the biological index, the community structure of reef fish of the Chaetodontidae is still stable. Compared to previous study, the present study shows that, within a period of 6 years, the condition of Chaetodontidae fish in Aceh Besar waters has increased in the number of species, abundance, and diversity of fish.

Analisis Kesesuaian Kawasan Perairan untuk Ekowisata Diving di Pulau Soreh Kabupaten Bintan

Tujuan penelitian ini adalah untuk mengetahui potensi ekologis serta analisis kesesuaian dan daya dukung kawasan perairan Pulau Soreh untuk ekowisata diving. Metode penelitian yang digunakan adalah metode survei dengan teknik pengambilan sampel secara purposive sampling yang terdiri dari 2 stasiun. Pengambilan data karang mengunakan metode PIT (Point Intersept Transect), data ikan menggunakan metode UVC (Underwater Visual Census), data kecerahan mengggunakan secchi disc, data kecepatan arus menggunakan botol berisi air dan dikat dengan tali berukuran yang sudah ditentukan, data kedalaman menggunakan bandul atau pemberat dengan tali yang sudah ditentukan ukurannya dan data sosial dengan metode wawancara. Berdasarkan hasil pengamatan potensi tutupan karang hidup sebesar 1–70 %, kecerahan perairan memiliki kecerahan berkisar 47,2-100%, jumlah jenis life form karang sebanyak 1-13 jenis, jenis ikan karang sekitar 4-14 jenis, kecepatan arus sebesar 10,82-13,36 cm/detik, kedalaman terumbu karang sekitar 3,50-10 meter, aksesibilitas sebanyak 1 aspek, dan biota berbahaya sebanyak 1 jenis. Kesesuaian wisata diving di Perairan P. Soreh pada setiap stasiun merupakan kawasan yang sesuai untuk dilakukan pengembangan ekowisata diving. Daya dukung terumbu karang untuk pengembangan ekowisata diving di Perairan P. Soreh pada setiap stasiun sesuai untuk dilakukan pengembangan wisata diving.

Results from a conservation initiative for parrotfishes in the Colombian Caribbean

Parrotfish (Family Scaridae) are a family of herbivorous fishes crucial to coral reef health, particularly for Caribbean reefs due to their declining coral cover. However, despite parrotfish are fully protected in some countries, they are still heavy fished in most of their Caribbean range. The consequences of this targeted fishery in the Colombian Caribbean are not fully understood due to a lack of local conservation and management resources. This research aimed to evaluate and enhance the conservation status and protection of parrotfish among local communities in the National Natural Park Corales del Rosario and San Bernardo. Underwater visual census surveys (UVC) were undertaken to evaluate reef fish community structure, and participatory education campaigns and activities were carried out with local communities to raise awareness about parrotfish ecology and their functional role in conserving Caribbean coral reef ecosystems of Colombia. UVC showed parrotfish to be dominant in the fish community, yet there was evidence of exploitation of large adults by selective fishing. Conflicts exist between the community and environmental authorities because fishing regulations are not clear, and the level of enforcement is insufficient. Parrotfish are sold to tourists, as ‘red snapper’ to fulfil high seafood demand since commercially valuable fish are now scarce. However, following intensive awareness-raising activities developed as part of this study, the community has started to recognize the vital ecological role of parrotfish in coral reef systems, and are suggesting a redrafting of fishing legislation by the environmental authorities, in order to recognise and incorporate the traditional fishing rights of human communities living within the MPA. Lobbying for the protection of parrotfish and inclusion of local communities in decision-making will take time, but this research represents the crucial first steps towards sustainable practice and cooperative alliances in the Colombian Caribbean.

Ocean literacy and scientific data acquisition through citizen science campaigns: a mixed approach in the Maltese Islands to collect information on Pinna nobilis and Pinna rudis

The genus Pinna includes two species in the Mediterranean Sea: Pinna nobilis and Pinna rudis. Both these species are under threat from multiple stressors. Pinna nobilis, in particular, has been exhibiting mass mortality events (MMEs) since 2016. The population and distribution of these species have never been comprehensively explored in the Maltese archipelago, and in this work, we collate information collected between 2006 and 2019 through a number of SCUBA underwater visual census monitoring programs. The logistical barriers surrounding SCUBA-based sampling techniques and the low-density distribution of these species constitute significant obstacles to an extensive conventional population assessment. Citizen science was thus also deployed in this study to supplement the data collected through SCUBA surveys: recreational SCUBA divers worked as citizen scientists, providing data on the distribution of these two endangered species from areas never explored before. This information can be used for assessing the conservation status of P. nobilis and P. rudis in Maltese waters, whilst contributing to the next generation of ocean-literate citizens.

Checklist of invertebrates and conspicuous fishes in rocky reefs and Sargassum beds in the North Pacific of Costa Rica

Introduction: The marine biodiversity is well known in some areas and for some marine ecosystems of the Pacific coast of Costa Rica. The marine sector of Área de Conservación Guanacaste, in the North Pacific of the country, is a priority area for conservation of marine and coastal biodiversity. Objective: Our aim was to increase the knowledge of marine biodiversity in a conservation priority site in Costa Rica and in poorly or scarcely studied marine ecosystems, such as rocky reefs and Sargassum beds, respectively. Methods: The study was conducted in Bahía Salinas and Golfo de Santa Elena in 2013. In January, four rocky reefs were visited; while in February three rocky reefs and one Sargassum bed were visited. We identified the macroinvertebrates and conspicuous fish species through underwater visual census methods (timed swim and band transects). The mean density of each species was estimated through band transects method. Results: A total of 25 invertebrates and 34 fish species were identified. We found a high number of species of invertebrates (23) and fish species (33) in rocky reefs, but few species on Sargassum beds (eight invertebrates and ten fish species). Species composition differed between marine ecosystems. Conclusions: Our study further evidence the limited knowledge of invertebrates and fish communities in these marine ecosystems in the North Pacific of Costa Rica. Considerably more surveys and field work are required to support management decisions that are backed by sound scientific knowledge.

Performance of a baited underwater video system vs. the underwater visual census technique in assessing the structure of fish assemblages in a Mediterranean marine protected area

Accurate, rapid and cost-effective fish assemblage monitoring is fundamental for marine protected area (MPA) management as a pivotal tool to verify whether and to what extent MPA conservation objectives have been achieved and to redefine these objectives in the framework of an adaptive management. Recently, there has been a sharp increase in the number of video-based methods to study fish fauna, such as baited remote underwater video (BRUV) systems, that, depending on the objectives of the monitoring, can provide complementary or additional data to the more commonly used underwater visual census (UVC). Even though BRUV systems have been widely used in a wide range of geographic contexts and habitats, their use in the Mediterranean basin is still sporadic and the evaluation of the efficiency of BRUV systems and whether they can be used to complement other techniques needs investigation. Thus, the objective of this study was to assess the performance of a BRUV system in a Mediterranean MPA and to evaluate its effectiveness in assessing the structure of fish assemblages (abundance and species richness) by comparing estimates with those obtained by the UVC technique. The fish fauna were monitored by BRUV and UVC in the Capo Caccia – Isola Piana Marine Protected Area (Sardinia, Italy), in July and October-November 2020, at four sampling sites and two areas, hundreds of meters apart, for each site. Overall, 46 taxa and a total of 3620 individuals were observed by BRUV, while 36 taxa and a total of 2995 individuals were observed by UVC. The species first observed in front of the camera’s field of view and able to reach the maximum abundance were the planktivores (Chromis chromis and Oblada melanura) followed by several carnivorous species belonging to the families Labridae, Serranidae and Sparidae, and lastly two carnivores (Mullus surmuletus and Mugilidae spp.) and some high-level predators (Dentex dentex, Seriola dumerili, Sphyraena viridensis, Dicentrarchus labrax). The maximum species richness and abundance were reached between 39 and 50 min. The cumulative species richness increased until around 30 min. Species richness was higher during the BRUV compared to the UVC monitoring. The consistency in findings between BRUV and UVC and a better performance of BRUV in detecting some species (mainly high-level predators), supports BRUV as an additional technique for describing and quantifying species richness and abundance also in the Mediterranean Sea. Based on the results of this study, the advantages/disadvantages, shortcomings, suggestions and resources needed for the two techniques are outlined.

Variasi Temporal Kelompok Ikan Terumbu Karang di Pulau Tidung Kecil Menggunakan eDNA Metabarkoding dan Sensus Visual

Coral reef fish are play key role in coral reef ecosystem. The presence of reef fish affected by antrophogenic and natural factors, such seasonal changes. This study aimed to asess the temporal variation of coral reef fish group in Tidung Kecil Island using eDNA metabarcoding and Undewater Visual Census. This research was conducted at December 2019 (West season) and August 2020 (East season). Target group are dominated in west season (64.1%) and east season (59.25%) using eDNA metabarcoding. While, major group fish are the highest relative abundance in both season by using Underwater Visual Census. Family Carangidae are the highest species richness (15 species) in wet season and Serranidae (3 species) in east season, respectively. Futhermore, famili Pomacentridae are the most richness species in west and east seasons 10 and 11 species respectively. Thus, it can be concluded these two methods are effective for monitoring structure or abundance of coral reef fish based on seasonal variation. Ikan karang menjadi indikator dalam menilai keanekaragaman hayati di ekosistem tersebut. Keberadaan ikan di ekosistem terumbu karang dapat dipengaruhi oleh faktor antropogenik dan faktor alam salah satunya perubahan musim. Penelitian ini bertujuan untuk menganalisis kelimpahan kelompok ikan terumbu karang di Pulau Tidung Kecil menggunakan eDNA metabarkoding dan Sensus Visual. Pengambilan data dilakukan pada bulan Desember 2019 (musim barat) dan Agustus 2020 (musim timur). Ikan target mendominasi pada musim barat dan timur dengan persentase sebesar 64.11% dan 59.25%. Sensus visual berhasil mendeteksi ikan mayor dengan persentase tertinggi 62.5% di musim barat dan 82.8% di musim timur. Famili Carangidae merupakan famili dengan jumlah spesies tertinggi di musim barat (15 species) dan Siganidae di musim timur menggunakan eDNA metabarkoding (3 species). Hasil UVC menunjukkan famili Pomcentridae memilki jumlah spesies tertinggi di kedua musim (11 dan 10 spesies) menggundakan sensus visual. Dapat disimpulkan bahwa kedua metode tersebut dapat menjadi pendekatan dalam monitoring struktur atau kelimpahan ikan terumbu karang berdasarkan musim.