GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • MDPI AG  (3)
  • 1
    Online Resource
    Online Resource
    From Staple Food to Scarce Resource: The Population Status of an Endangered Striped Catfish Pangasianodon hypothalamus in the Mekong River, Cambodia
    MDPI AG ; 2023
    In:  Sustainability Vol. 15, No. 11 ( 2023-06-05), p. 9103-
    Details
    In: Sustainability, MDPI AG, Vol. 15, No. 11 ( 2023-06-05), p. 9103-
    Abstract: Striped catfish Pangasianodon hypopthalmus (Sauvage, 1878) is a flagship catfish species of the Mekong River region, a commercially valuable food fish that is important in freshwater fisheries, and a popular aquaculture species in many Asian countries. The species was assessed as “Endangered” by the International Union for Conservation of Nature (IUCN) due to range contraction and declining abundance, though the status of the species’ wild population in Cambodia, a critical habitat for the species, is not well understood. Here, we assess the population status of the striped catfish in Cambodia using multiple sources, including time-series catch data and length frequency distribution data from a commercial fishery (stationary trawl bagnet or dai) operated in the Tonle Sap River from 1998/99 to 2017/18 and larval drift data monitored in the Mekong River in Phnom Penh from 2004 to 2018. We found that there was a significant decline (R2 = 0.54, p = 0.0002) in the catch (metric tonnes) of the striped catfish from the commercial dai fishery over the last two decades. Similarly, length-based indicator analysis indicates that striped catfish mean length and abundance have both declined over the study period, raising concerns about the sustainability of river catfish fisheries. Moreover, long-term larval drift monitoring in Mekong River shows that there was a marginally significant decline in the quantity of striped catfish larvae/juvenile drifting downstream to the lower floodplain over the last decade. Changes in flood index (extent and duration of flood) in the Tonle Sap floodplain affected by the Mekong’s flow are likely key factors driving the decline of the wild populations of the striped catfish. Both larval fish abundance and floodplain fish harvests have a significant positive relationship with Mekong flow and flood extent. Indiscriminate fishing exacerbates pressures on striped catfish stocks. Therefore, actions such as maintaining natural seasonal flows (flood timing, extent, and duration) to the Tonle Sap floodplain and protecting migratory fish stocks from overharvest and habitat fragmentation are essential to the persistence of stocks of striped catfish and other large-bodied migratory fishes that utilize both the Cambodian Mekong and Tonle Sap floodplains.
    Type of Medium: Online Resource
    ISSN: 2071-1050
    URL: Article
    DOI: 10.3390/su15119103
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2518383-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Declines in the Mekong’s Megadiverse Larval Fish Assemblages: Implications for Sustainable Development
    MDPI AG ; 2023
    In:  Sustainability Vol. 15, No. 18 ( 2023-09-11), p. 13535-
    Details
    In: Sustainability, MDPI AG, Vol. 15, No. 18 ( 2023-09-11), p. 13535-
    Abstract: Migratory fishes of the Mekong Basin are facing challenges from human-induced stressors. Quantifying the patterns of fish’s early life stages provides important information on spawning seasons, spawning and nursery habitats, reproductive strategies, migration and dispersal patterns, and stock status. However, the ecology of the Mekong larval fishes, including patterns and drivers of larval fish dispersal, is not well understood. Here, we investigate the temporal variability of drifting larval and juvenile fish assemblages in the Cambodian Mekong River and identify their environmental drivers using long-term (10 year) daily fish larval/juvenile data collections. We found that, in the Mekong main channel, the larval and juvenile assemblages were dominated by longitudinal migrants from the families Cyprinidae and Pangasiidae. Peak abundance and richness were found to occur in July and August, respectively. We detected a significant decline in larval and juvenile abundance and richness over the study period. Cross-wavelet analysis revealed that water levels always lead larval abundance, but lag richness. In addition, cross-correlation analysis observed that peak abundance and richness occurred eight weeks and one week, respectively, before the peak water level. We also discovered that species abundance and richness had a strongly positive relationship with maximum water levels. Variation in fish larval and juvenile abundance and richness was also related to total phosphorus, nitrate, alkalinity, and conductivity. Maximum water levels and the key water quality parameters (e.g., phosphorus, nitrate, alkalinity, and conductivity) significantly influence larval and juvenile fish abundance and richness patterns. Therefore, safeguarding natural seasonal flows, especially maximum flows associated with the peak flood pulse, as well as maintaining good water quality, are key to the reproductive success of many migratory fishes and effective dispersal of offspring to the lower floodplain for nursing, rearing, and growth. Clean and unregulated rivers support productive and diverse fisheries.
    Type of Medium: Online Resource
    ISSN: 2071-1050
    URL: Article
    DOI: 10.3390/su151813535
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2518383-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Cambodian Freshwater Fish Assemblage Structure and Distribution Patterns: Using a Large-Scale Monitoring Network to Understand the Dynamics and Management Implications of Species Clusters in a Global Biodiversity Hotspot
    MDPI AG ; 2020
    In:  Water Vol. 12, No. 9 ( 2020-09-08), p. 2506-
    Details
    In: Water, MDPI AG, Vol. 12, No. 9 ( 2020-09-08), p. 2506-
    Abstract: Mekong River Basin is one of the world’s fish biodiversity hotspots. Fisheries of the Cambodian Mekong are characterized by high diversity and productivity. However, few studies have focused on broad scale patterns and fish assemblage structure of this important system at a national level. Here, we describe spatial and seasonal variation in fish assemblages by analyzing one year of daily fish catch data sampled at 32 sites covering Cambodia’s main inland water bodies. We recorded 125 fish species. Four clusters were distinguished based on assemblage composition similarity, and 95 indicator species were identified to characterize each of the identified assemblage clusters. High diversity fish assemblages were associated with the upper Mekong system and Mekong/Bassac/Tonle Sap Rivers in Kandal Province and southern Tonle Sap Lake while lower diversity assemblages were observed in the Mekong River in Kratie and the northern area of the Tonle Sap Lake. We find significant variation in the assemblage composition between wet and dry seasons, indicating strong seasonal species turnover within clusters. Length–weight relationship analysis indicated a negative allometric growth among a majority of indicator species, reflecting suboptimal conditions for growth. Our study establishes contemporary structure and diversity patterns in the Lower Mekong River system of Cambodia, which can be used to map fish biodiversity hotspots and assess key indicative fish stocks’ statuses for conservation and management.
    Type of Medium: Online Resource
    ISSN: 2073-4441
    URL: Article
    DOI: 10.3390/w12092506
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2521238-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...