Fish Biodiversity Research Articles

Increasing fish biodiversity in high elevation Albertan lakes in response to global environmental change over the past 50 years

IntroductionThe diversity of freshwater fishes is threatened by multiple environmental stressors, including climate change, alterations in land use, and introduction of non-native species. However, the quantification of temporal biodiversity in freshwater communities is limited. Here, we asked: i) how has alpha (species richness), beta (changes in freshwater species composition), and gamma diversity (total species diversity in a landscape) changed over time for lakes over a 50 year period?; and ii) What are the climatic, land use, and lake morphological drivers associated with higher diversity?MethodsWe assembled a database of fish species occurrence from 20 lakes across subalpine and alpine regions in Alberta from 1970-2019, in addition to lake morphological, climatic, and land use characteristics of the watersheds. ResultsWe observed an overall increase in alpha, beta, and gamma diversity from the 1970s to 2009s. However, all measures of diversity declined from 2010-2019. We found that more lakes and species assemblages were influenced by species gains, rather than species losses (with the exception of the last decade of sampling). DiscussionGenerally, we found that coolwater species were expanding and coldwater fishes were being lost throughout our study lakes. We highlight temporal heterogeneity in fish biodiversity responses to substantial environmental pressures in this region.

Diadromous fish run assessment: a double-observer model using acoustic cameras to correct imperfect detection and improve population abundance estimates

IntroductionDiadromous fish populations have strongly declined over decades, and many species are protected through national and international regulations. They account for less than 1% of fish biodiversity worldwide, but they are among the most perceptible linkages between freshwater and marine ecosystems. During their migration back and forth, diadromous fish species are subjected to many anthropogenic threats, among which river damming can severely limit access to vital freshwater habitats and jeopardize population sustainability. Here, we developed a method based on a double-observer modeling approach for estimating the abundance of diadromous fish during their migration in rivers.MethodsThe method relies on two independent and synchronous records of fish counts that were analyzed jointly thanks to a hierarchical Bayesian model to estimate detection efficiencies and daily fish passage. We used simulated data to test model robustness and identify conditions under which the developed approach can be used. The approach was then applied to empirical data to estimate the annual silver eel run in the Touques River, France.ResultsThe analysis of simulated datasets and the study case gives evidence that the model can provide robust,accurate, and precise estimates of detection probabilities and total fish abundance in a set of conditions dependent on the information provided in the data (annual distribution of fish passage, annual number of observation, pairing period, etc.).DiscussionThen, the method can be applied to various species and counting systems, including nomad acoustic camera devices. We discuss its relevance for programs on river continuity restoration, notably to quantify population restoration associated with dam removals.

Effects of hydrological and spatial seasonality on taxonomic and functional diversity of fish assemblages in an Amazonian floodplain lake

AbstractThe floodplain lakes of the Amazon constitute one of the most important aquatic systems in terms of fish biodiversity. These ecosystems are influenced by the flood pulse, which in turn, affects the behaviour of fish communities within this lake ecosystem. In this study, we tested the hypothesis that the facets of taxonomic and functional diversity may be influenced by the conditions of ‘patches’ of internal habitats, considering the margins and central environments of a floodplain lake in the Amazon. Lake Cujubim, located on the right bank of the Madeira River, was evaluated via fisheries carried out in the high‐water and low‐water phases, during the day and night, and considering two location strata. The results suggest that the absence of significant differences in alpha taxonomic diversity between the two phases may be a possible seasonal mischaracterisation in Lake Cujubim attributed mainly to dam constructions along the Madeira River. Apparently, no major differences occur in the assembly of fish in terms of their taxonomic and functional characteristics, regardless of luminosity. In the strata of the locations, demonstrates noticeable habitat patches, with the margins being bioregions with high incidences of individuals of the Engraulidae family, confirmed by both taxonomic and functional diversity (alpha and beta). It can be seen that, even in connected lakes, there are differentiated metacommunities between the bioregions, thus forming patches of habitat, and that the shores of the lake, especially those located in proximity or distant from the river, are more suitable areas for food and refuge.

LITERATUR REVIEW: PEMANFAATAN METABARCODING DNA LINGKUNGAN UNTUK MENGANALISIS KEANEKARAGAMAN HAYATI IKAN

Background: Environmental DNA (eDNA) metabarcoding is a new method for assessing biodiversity in which samples are taken from the environment via water, sediment or air from which DNA is extracted, and then amplified using common or universal primers in a polymerase chain reaction and sequenced using next-generation DNA. sequencing to produce thousands to millions of sequences. From this data, the presence of species can be determined, and overall biodiversity can be assessed.. Methods: The method used is a literature review using reputable national and international journals Results: Based on the results of the literature review, the use of eDNA metabarcoding can be used to analyze fish biodiversity. eDNA metabarcoding can be analyzed with primary data, databases, and bioinformatic pipelines. Conclusion: eDNA metabarcoding has been widely used to study fish communities in lakes and rivers, as well as coastal fish communities. Despite its considerable ability to detect fish species in large aquatic systems, many methods still need to be understood to improve the quality of primers, databases, and pipelines for analyzing fish biodiversity

The diversity, distribution, biomass, and conservation status of ichthyofauna of the Singkil peat swamp in Aceh Province, Indonesia

Abstract. Razi NM, Nasir M, Khalidin K, Savira D, Najmi I, Mahfud M, Dermawan F, Fadli N, Muchlisin ZA. 2023. The diversity, distribution, biomass, and conservation status of ichthyofauna of the Singkil peat swamp in Aceh Province, Indonesia. Biodiversitas 24: 6661-6674. The land conversion of the Singkil peat swamp into oil palm plantations poses a significant threat to the aquatic ecosystem, with potentially detrimental consequences for fish biodiversity. Several reports showed that there was no data on fish diversity in the Singkil peat swamp despite the damage occurring in the area. Therefore, this study aimed to analyze the diversity, distribution, biomass, and conservation status of Ichthyofauna in the Singkil peat swamp waters. Sampling was carried out at 13 locations from July 2023 to August 2023, and the samples were caught using gill nets, casting nets, fishing rods, and traps. A total of 934 samples were collected during the sampling, belonging to 39 species, 31 genera, and 26 families. The results showed that Cyprinidae was the most dominant family, with an average diversity index of 1.23, indicating the medium category. The average dominance index was 0.42, which was placed in the low category. Channa striata (Bloch, 1793) and Trichopodus trichopterus (Pallas, 1770) had the highest frequency of occurrence and were found in seven locations out of 13 surveyed. Furthermore, these species were categorized as frequently found based on their availability. The average fish biomass was 288.75 kg/ha, with C. striata having the largest value. Among the 39 fish species obtained, 3 species were classified as near threatened, including Anguilla bicolor (McClelland, 1844), Mystus bimaculatus (Volz, 1904), and Kryptopterus minor (Roberts, 1989), while 1 invasive sample was recorded, namely Oreochromis niloticus (Linnaeus, 1758) in one location.

Diversity of fishery resources and catch efficiency of fishing gears in the Feni River (Bangladesh)

A thorough examination of fish diversity indices, gear efficiency, catch composition, and decline causes of fish diversity was carried out in the Feni River (Bangladesh). Monthly data collection took place from July to December 2023 at three stations of the river. A total of 8 fish species under 7 orders and 8 families were recorded. The order Perciformes was the most prevalent, representing 30% of the total. Approximately half of the identified species are classified as least concern, while the remaining 4 species are classified as Not Threatened (12.5%), Vulnerable (12.5%), Endangered (12.5%), and Critically Endangered (12.5%). The mean values of the Margalef’s richness (d), Pielou’s evenness (J), Simpson’s index (1-D), Shannon-Weaver diversity (H), and 0.973±0.002 were calculated as follows: 1.720±0.139, 0.699±0.112, and 0.248±0.034, respectively. Based on the Bray-Curtis similarity matrix, two groups were observed at a similarity of 58% within six months across the three sites. The chandi net and ghera net recorded the highest CPUE (kg gear-1day-1) at 5.93±0.966 and 0.53±0.041, respectively. The highest fish catch was recorded in July (2249 ± 668.71 kg), while the lowest was in October (1564 ± 465.05 kg). There was no significant difference (p>0.05) in the monthly fish catch. Fish biodiversity in the Feni River is declining day by day as a result of pollution, overfishing, the use of harmful gear, and a lack of optimal water and pollution. To improve and conserve fish species in the Feni River, it is strongly advised that appropriate fishery management techniques should be applied, that overfishing be closely monitored, and that fishermen be made more aware of their rights.

Valorizacija ljušture invazivnih rakova iz reke Dunav (Faxonius limosus) - ekstrakcija i karakterizacija proteina

In order to deal with invasive crayfish (Faxonius limosus) impact on the native crayfish, as well as fish biodiversity in the Danube River, a possible solution would be to find and adopt mechanisms for its utilization for novel valuable product production. Apart from utilizing edible parts for novel food products, the shell waste can also be considered a source of valuable compounds. The complex structure of the shell mainly consists of three basic compounds: chitin, protein and minerals-mainly calcium carbonate. In this study, shell waste proteins were extracted using three extraction methods. The first method involved using naturally present enzymes (proteases and lipases) in crayfish wastes to recover proteins through an autolysis process. To accelerate the process, UV radiation was used. The remaining two extraction methods were alkaline extraction of proteins, wherein one method alkaline extraction was applied directly to the shell waste, and the other method, alkaline extraction followed an acidic demineralization step of the shell waste. The obtained protein concentrates were analysed for yield, crude protein content, DPPH radical scavenging ability, amino acid content, and structure. The results have shown that a similar percentage of protein content was obtained by all three methods: 67.20-68.03 %, but the extraction yield was considerably different. Alkaline deproteinization with or without the step of demineralization resulted in a 9.20-10.98 % yield, while UV radiation accelerated autolysis resulted in only a 3.41 % yield. Although protein extraction without using exogenous enzymes or chemicals is a very interesting approach, a drawback of this approach is the low process yield. FTIR spectroscopy revealed a secondary structure that was similar in all three concentrates, according to peak deconvolution, with the autolytic concentrate differing to a lesser extent, showing a slightly higher share of b-sheet structures. The DPPH assay revealed high antioxidant activity of the concentrates (72.00-88.06 %), probably originating from active peptides derived from proteins and residual carotenoids, mainly astaxanthin.

Biodiversity of freshwater fish in Pangalengan District, Bandung, West Java

Java Island has about 132 freshwater fish species compared to the other major islands in the Sundaland region, such as Sumatra, which has about 589 species. This study aims to reveal and identify the diversity of freshwater fish around Pulosari Village, Pangalengan District. Exploration activities were conducted in river and lake habitats of Pangalengan District, Bandung Regency, West Java. Specimens were collected by authors and local fishermen using three fishing gears: gill nets, fishing rods, and fish scrappers. Immediately after collecting, fish were documented using a digital camera to obtain their original color. In this study, a total of 11 freshwater fish species belonging to 10 families were found. Some species are recognized as introduced fish.

PISCINE BIODIVERSITY CHARACTERIZATION OF THE STUBBS CREEK, NIGER DELTA, NIGERIA RECEIVING OIL SPILL EFFLUENTS

A parsimonious survey of the fish biodiversity of the Stubbs Creek, a coastal freshwater/ blackwater stream in the Niger Delta, Nigeria was conducted. The all Teleostei fishes comprised a high taxonomic heterogeneity with 32 species, 24 genera and 17 families. They were organized in three eco physiological assemblages (the primary freshwater, secondary freshwater and peripheral Assemblages) and four mesohabitat assemblages (benthic, benthopelagic, pelagic and epipelagic assemblages). Approximately 84.4% of the fish species were found to be equipped with a variety of biophysical life enhancement devices which enable them to optimally exploit the available resources of the habitat space. The Stubbs Creek has the potential of producing about 27.2 tonnes km-2 year-1 of fish flesh for human consumption, barring the impacts of oil spill effluents from a major oil producing company within the Stream basin/catchment area. Elevated levels of Hydrocarbon (PAHs) and heavy Metals, far above WHO recommended levels were observed in this study. It is figured that the results of this study qualify the Stubbs Creek to be considered as ‘Stream of Special Scientific Interest‘ (SSSI) for management and conservation purposes

Change in Reef Fish Assemblages along Depth Gradient at Gili Rakit and Gili Lipan Marine Protected Areas (MPAs)

Since 2010, Marine Protected Areas (MPAs) have been established in Indonesia to ensure the sustainable management of coral reef ecosystems. This study examines fish assemblages across varying depths and MPAs management areas, specifically assessing the suitability of Gili Rakit and Gili Lipan MPAs. The study concludes that deeper coral reefs have higher reef fish abundance, with a majority of carnivores, planktivores, and omnivores. Gili Taekebo has the lowest abundance and species richness, while Pulau Lipan has the highest. The target reef fish are primarily found in the core zone, rehabilitation, and open access management types. Based on the findings, MPAs should prioritize sites with gradient depth coral reefs and complex habitats to enhance reef fish biodiversity richness. Takad Tabampang and Pulau Bedil are recommended as sustainable fisheries management types, while Gili Taekebo could benefit from rehabilitation or open access management. Pulau Lipan and Labajo may benefit from target fish re-stocking programs.

Comparison of traditional and molecular surveys of fish biodiversity in southern Te Wāhipounamu/Fiordland (Aotearoa/New Zealand)

AbstractEffective management of biodiversity requires regular surveillance of multiple species. Analysis of environmental DNA (eDNA) by metabarcoding holds promise to achieve this relatively easily. However, taxonomy‐focused eDNA surveys need suitable molecular reference data, which are often lacking, particularly at the species level and for remote locations. To evaluate the comparability of environmental DNA surveys and traditional surveys in a real‐life case study in a marine area of high conservation value, we conducted a biodiversity survey of the fish in remote and pristine Te Wāhipounamu/Fiordland (Aotearoa/New Zealand), incorporating multiple data sources. We compared eDNA‐derived species identifications against Baited Remote Underwater Video (BRUV) data collected at the same time and locations as eDNA. We also cross‐referenced both eDNA and BRUV data against literature and the Ocean Biodiversity Information System (OBIS), with literature and OBIS data representing a summary of multiple traditional surveying approaches. In total, we found 116 fish species in our study area. Environmental DNA detected 43 species; however, only three of those species overlap with species known from the literature, OBIS, or our BRUV analyses. A total of 61 fish species were known from the region from the literature, while OBIS listed 28 species, and our BRUV analyses picked up 26 species. BRUV data coincided more strongly than eDNA data with literature and OBIS data. Twenty of the 26 species detected by BRUV were known from literature and OBIS. We argue that limitated DNA reference databases are the main cause of this discrepancy, and our results indicate that eDNA of rare and endangered species can be detected if matching reference data were available. Environmental DNA analyses can only identify species present among reference data and with relaxed taxonomic assignment parameters may converge on relatives of detected species if the actually existing species themselves are missing among reference data. However, the high number of species detected by our eDNA analyses confirms that eDNA could be a powerful tool for biodiversity surveys if suitable investments in local reference databases were made.

Putting eDNA to the test: A field comparison of eDNA metabarcoding to established protocols for assessing biodiversity in Missouri's Ozark Highland streams

AbstractAquatic biodiversity monitoring to inform conservation and management efforts in‐stream systems has increasingly begun to incorporate environmental DNA (eDNA)‐based sampling methods. We conducted a comparison of eDNA metabarcoding to a traditional protocol of combined seining and electrofishing methods to assess fish biodiversity of wadeable stream sites in six separate drainages in the Ozark Highlands of Missouri (USA). The study further focused on the headwaters of the Meramec River, which included 11 sites and seasonal sampling (summer and winter). We compared estimates of diversity across sampling methods, assessed the influences of water flow (depth, velocity, and discharge) and season, and tested the effects of sampling method and site locality on fish assemblage composition. eDNA sampling detected approximately double the number of species compared to traditional methods, providing higher diversity estimates while maintaining the relative ranking of sites. eDNA detection probabilities were positively associated with stream depth and velocity and were generally higher in summer than in winter but not for all species. Estimated species richness was positively associated with discharge for both methods but the relationship was stronger with eDNA sampling. Assemblage differences between tributary and mainstem sites were attributable to a small number of species that were found predominantly in one stream size category or the other, indicating that eDNA was sensitive to within‐drainage assemblage structure relationships. We highlight improved species detection, a more comprehensive understanding of assemblage structural dynamics, and the potential ability to integrate data across sampling methods as important benefits that encourage the use of eDNA metabarcoding as a primary collection method in future stream biodiversity assessment and monitoring programs.

Assessing fish diversity in abandoned mining ponds in Madre de Dios, Peru, using environmental DNA

AbstractThe Peruvian region of Madre de Dios is a biodiversity hotspot located in the Andean‐Amazon region. Since the 1970s, it has experienced the harsh effects of artisanal and small‐scale gold mining (ASGM), which has transformed the primary forests into numerous small mining ponds left abandoned after extraction. Preliminary surveys indicate that these ponds are being recolonized by surrounding biodiversity. These assessments are typically carried out using traditional methods that are costly, difficult to deploy at multiple locations, and have raised safety concerns. In this context, environmental DNA (eDNA) becomes a useful tool for biodiversity monitoring due to its simplicity for sample collection and performance to identify taxonomic groups. In this study, we evaluated fish biodiversity in two mining ponds created by ASGM along with two nearby pristine lakes, unimpacted by mining operations but also influenced by seasonal flooding. We compared two alternative eDNA processing methods and contrasted our results with historic data from traditional biodiversity monitoring. Both eDNA‐based methods yielded comparable results, varying only in logistic requirements and costs. In total, we detected 85 fish MOTUs (22 at the species level) from 5 orders, 22 families, and 41 genera. Some of the species identified with eDNA were rarely registered by traditional monitoring, and we could identify 6 genera associated with ASGM mining ponds only. A major restriction of the eDNA approach in this location was the insufficient local taxa registered in genomic databases which limited our taxonomic resolution. Despite this limitation, our results indicate that eDNA could be a powerful tool for biodiversity estimations in the Western Amazon, identifying more taxa, with much less time and money invested than traditional monitoring. Our results also confirm that abandoned mining ponds are being recolonized by surrounding ichthyofauna, reaching richness levels above nearby unmined oxbow lakes used as reference.

Perspectives from an eDNA metabarcoding pilot project in the Banggai MPA, Central Sulawesi, Indonesia

The Banggai MPA is one of many Indonesian MPAs established or reestablished as a result of the shift from regency to provincial level governance over waters 0–4 NM from shore under Act 23/2014. The MPA covers a substantial proportion of Banggai Archipelago coastal ecosystems and around 90% of endangered Banggai cardinalfish (Pterapogon kauderni) endemic habitat. An expedition in 1998 reported high fish biodiversity; however, logistics and taxonomic expertise requirements mean that similar methods are not realistic for collecting baseline or monitoring biodiversity data to support MPA management. A pilot project in 2018 collected water samples (four shallow-water coastal sites, three replicates per site) around Banggai Island for environmental DNA (eDNA) metabarcoding using two molecular markers: COI mtDNA and 12S rRNA. COI data were overwhelmingly dominated by a few phytoplankton species, reflecting challenges using this marker in areas with dense phytoplankton, and could not be analyzed further. The 12S rRNA sequences were processed and aggregated into amplicon sequence variants (ASVs) using the Anacapa Toolkit. These data provide a snapshot of fish diversity by site, although accumulation curves indicate three samples per site is insufficient to provide a comprehensive record. Identified taxa overlapped and exceeded in number those detected in 1998. The percentage of ASVs unassigned at species and genus level (e.g., gobies and cardinalfishes) and taxonomic ambiguities indicate a need for combined classical taxonomic and barcoding studies to enhance nucleotide databases (GenBank/BOLD), ideally with regional voucher specimen repositories. Furthermore, the study revealed the need for further capacity building in metabarcoding data analysis.

Health Assessment of the Duliujian River Ecosystem Based on Fish Biodiversity Index

Health Assessment of the Duliujian River Ecosystem Based on Fish Biodiversity Index

Status of Fish Biodiversity in the Sindphana River Dam Near Shirur Kasar, District Beed, Maharashtra, India

Fish biodiversity studies were undertaken from January 2012 to December 2012 to census commercially important fishes in the Sindphana Dam. The present paper deals with the variety and abundance of freshwater fishes in the Sindphana Dam near Shirur Kasar Dist. Beed [M.S] India. The results of the present investigation reveal the occurrence of 44 fish species belonging to 7 orders, 15 families, and 26 genera. Among the collected species order Cypriniformes was most dominant constituting 50% followed by order Siluriformes constituting 18%, order Perciformesconstituting 18 %, orders Osteoglossiformesand Synbranchiformes constituting 5% and orders Mugiliformesand Beloniformes constituting 2 %of the total fish species. Fish biodiversity indices species richness 44 in the total number of species (N0), 3.73 in Margalef’s index (R1), and 0.97 in the Menhinick index (R2). Species diversity was 0.47 in the Simpson index (), 1.16 in the Shannon-Weiner index (H’), 2.98 in abundant species (N1), and 2.80 in very abundant species (N2). Species evenness was 0.42 in (E1), 0.21 in (E2), 0.17 in (E3), 0.95 in (E4), and 0.97 in (E5). Bangladesh J. Zool. 51(2): 155-164, 2023

Pengkayaan Sumberdaya Ikan di Oxbow Melalui Penerapan Artifisial Habitat Oleh Nelayan Desa Rantau Baru Kecamatan Pangkalan Kerinci Kabupaten Pelalawan Riau

This community dedication is aimed at informing the community about the creation of a new fish habitat by floating a set of artificial habitat units in the selected zone based on oxbow batimetry, so that the fish resources in the oxbows remain available. The dedication activities were carried out in the Rantau Baru Village, Pangkalan Kerinci district of Pelalawan Regency, and the delivery of material was carried out on August 2, 2023. There are 30 participants in this selection, consisting of the village equipment and the oxbow fishermen in the New Rantau Village. The materials to be provided for this dedication are: (a) Oxbow and its uses; (b) biodiversity of fish and public waters; (c) threats to fish biodiversity; (d) artificial habitat; and (e) methods of creation, operation, and maintenance of artificial habitat. The method used in the implementation of this activity is to survey the field first, then conduct deliberations in the form of lectures and interactive discussions, followed by demonstrating the artificial creation of habitats and placing the tools in the oxbow. The results of the evaluation of the change in knowledge carried out on 30 participants in the service to the community showed that 5 people (16.7%) have been able to absorb the material given with the preaching very well, 13 people (43.3%) can absorb materials given with good preaching, 10 people (33.3%) can absorb material with sufficient preaching, and 2 people (6.7%) could absorb material with less preaching. As for the impact on implementation in the field, there has been a process of dissemination of knowledge to fishermen carried out by community leaders. So that the diversity of fish in public waters (especially the oxbow lake) that exists in the Rantau Baru Village can be well awakened.

Length-Weight Relationships and Growth Patterns of Eight Indigenous Fish Species from Lancang River, Southwest China

The Lancang-Mekong River watershed has extremely high fish biodiversity. With the rapid population growth and economic development in the river basin, fish diversity and fishery resources of this river are experiencing serious threats. Basic biological information on most fish species in the Lancang River, required to improve conservation in this area, is limited. This study aimed to provide new estimates of length-weight relationships (LWRs) by using the linear regression of W = aLb for eight indigenous fish species from the Lancang River, Southwest China. From 2018 to 2021, 534 specimens belonging to 3 families and 8 genera were collected using various types of fishing techniques. Standard length (SL) and body weight (BW) of each specimen were measured to the nearest 0.1 cm and 0.1 g, respectively. This study presents the first public records of LWR parameters of Schizothorax lissolabiatus, Poropuntius huangchuchieni, Tor sinensis, Scaphiodonichthys acanthopterus, Mystacoleucus lepturus, Hemiculterella macrolepis, Glyptothorax lampris, and Schistura porthos. The range of b values for the LWRs was 2.5378–3.1732, and the r2 values for all LWRs estimates ranged from 0.9102 to 0.9952. Intraspecific difference of b values across population and/or season was observed in S. lissolabiatus, T. sinensis, P. huangchuchieni, S. acanthopterus, and M. lepturus. The range of mean condition factor (K) and mean relative weight (Wr) was 0.97–2.39 and 100.29–108.18, respectively. This study updated information for FishBase and provided new record of maximum standard length for five species, namely, S. lissolabiatus, P. huangchuchieni, T. sinensis, S. acanthopterus, and M. lepturus. The findings of this study are essential for the management and conservation of locally indigenous fish and fisheries.

Ecological impacts of management practices in agricultural drain networks: a literature synthesis

Drain networks are essential for connecting farming landscapes to waterways to help mitigate floods and convey water downstream. Unfortunately, drains also convey nutrients and sediments from surface or tile drain run-off, which can impact critical habitats for benthic macroinvertebrates and fish communities, including many species at risk of extinction. To bridge discussions around drainage and ecological values associated with sustainable management of water resources in drainage systems, we conducted a comprehensive literature synthesis on the ecological impacts of drain management practices (DMPs) and best management practices (BMPs). To inform drain management at a regional scale, we extracted key findings from 111 peer-reviewed studies with similar physical attributes and management contexts representative of southwestern Ontario’s agricultural landscapes. Across studies, impacts of management practices were assessed over relatively short time periods (1 month − 2 years), limiting understanding of the long-term impacts and ecological or management trade-offs. Frequently measured water quality indicators included carbon, nitrogen, and phosphorus concentrations. Fish biodiversity and abundance were the most commonly measured biodiversity indicators. Recent studies suggest that biodiversity in drain systems is highly resilient and consists of common species that can cope with management activities. Despite literature gaps, findings suggest that while both practices maintain critical drain functions, trade-offs between flood mitigation, biodiversity and water quality remain underexplored. BMPs have the potential to offer multiple co-benefits and greater uptake across the region and across agricultural landscapes in Canada yet place-based evidence is lacking. Cross-sector partnerships can help bolster efforts to critically assess and implement local solutions.

Considerations needed for analysing data from the Swedish Electrofishing RegiSter (SERS), with special reference to the RivFishTIME database of long-term riverine fish surveys

The published database RivFishTIME (Comte et al. 2021, Global Ecology and Biogeography, doi: 10.1111/geb.13210) includes a large section of time-series data on fish abundance in Swedish rivers from the Swedish Electrofishing RegiSter, SERS. Knowledge about the limitations of the source data are important when extracting and analyzing data and with this brief note we provide some details that may be helpful for interpreting the Swedish time-series. The note highlights the importance of linking vital metadata to extracted focal data when constructing new databases, especially concerning time series data from monitoring programs conducted in non-randomly selected sites with human environmental impacts. Many of the SERS data come from rivers that have been affected by human impact, e.g. liming to mitigate environmental acidification and hydropower dams, since before monitoring was initiated. Data in SERS are also biased towards shallow salmonid habitats, due to the configuration of Swedish monitoring programs. Hence, data from many rivers are not representative of their fish biodiversity in general. This information is vital for appropriate interpretation of fish biodiversity trends. For RivFishTIME analyses considerations are important since Swedish data constitutes a large proportion of the database. We also provide background information about SERS and references to other Swedish databases containing complementary information. Finally, we provide contact information of the SERS database curators, who can assist prospective analysts with data extraction from SERS.