Session 33: Ichthyology Conservation & ManagementRoom: Room 206D2022-07-30 08:30 - 09:30 |
| Moderator: Tom Munroe |
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1. 08:30 Extinction Risk Assessments for Members of the Flatfish Suborder Pleuronectoidei: A Global Perspective on Conservation Evaluations for a Diverse Taxon. Thomas Munroe*, Smithsonian Institution; Gina Ralph, Old Dominion University; Christi Linardich, Old Dominion University munroet@si.edu
Flatfishes constitute a diverse group of interesting fishes characterized by bilateral asymmetry. They occur in shallow to moderately deep (ca. 2000 m) demersal habitats worldwide. Most species inhabit marine waters, several reside within estuaries, and a limited number occur strictly in freshwater. Flatfishes range from 2.5 to 365.0 cm. Larger species support major commercial and recreational fisheries, while smaller, primarily tropical, species are an important component of non-selective trawl fisheries. In collaboration with 20+ international experts, we applied IUCN Red List methodology to assess conservation status of 811 flatfish species. Nearly 4% of species for which data are available are considered threatened (range 2-43%). Most threatened species are large, heavily exploited members of the Pleuronectidae, many of which are also impacted by warming waters associated with climate change. However, this family also includes key examples of species with well-managed fisheries, particularly those occurring in the northeast Pacific Ocean. In contrast, the speciose families, Soleidae, Bothidae, and Cynoglossidae, record high numbers of Data Deficient species. Many of these species experience high levels of anthropogenic threats, though population-level changes could not be quantified because of limited data. Taxonomic issues can impede accurate application of IUCN Red List criteria, while assessments themselves highlight data gaps and can inspire new avenues for research. For example, inconsistencies in taxonomy applied to several subspecies of Platichthys flesus have implications when assessing conservation status of these taxa. This first comprehensive extinction risk assessment of flatfishes forms the baseline for evaluating future changes in biodiversity of these fishes. |
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2. 08:45 Global ‘BioLake’ Climate Layers for Aquatic Invasive Species Risk Assessment. Ryan Burner*, U.S. Geological Survey, Upper Midwest Environmental Sciences Center; Wesley M Daniel, U.S. Geological Survey, Wetland and Aquatic Research Center
; Richard Erickson, U.S. Geological Survey, Upper Midwest Environmental Sciences Center ryan.c.burner@gmail.com
Aquatic invasive species (AIS) are responsible for at least US$23 billion in global damages annually. This makes early identification of potential invaders imperative so that managers and regulators can focus prevention efforts on species of highest risk. Yet climate matching models often rely on air temperature-based climate layers, which likely limits their effectiveness for aquatic species. We generated twelve global lake temperature-based climate layers (‘BioLake’) that correspond to air temperature-based CHELSA BioClim variables. To compare the value of BioLake vs. BioClim (and a null model) for AIS, we predicted invasion risk across the contiguous U.S. for 50 established AIS using climate in their native ranges and the climatchR R-package. Predicted risks of invasion at U.S. sites currently occupied by each AIS were relatively high in both climate models, but higher with BioClim than BioLake. However, both models outperformed the null model by a similar margin. Predictive ability was highest for species that originated in climates most different from North America (e.g., the tropics), and was on average slightly higher for plant species than for animals. We demonstrated the utility of using native range climate to assess invasion risk for potential future invaders of concern. Our novel lake temperature-based climate layers provide an additional resource to aid AIS managers and regulators, and further improvements to global lake temperature models will allow increasingly refined predictions. |
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3. 09:00 Taxonomy of Invasive Hypostomus (Loricariidae) in Costa Rica and the US, using an Integrative Approach. Taegan Perez*, Department of Biological Sciences; University of Toronto Scarborough; Arturo Angulo, Museo de Zoología y Centro de Investigación en Ciencias del Mar y Limnología: Universidad de Costa Rica; Nathan Lujan, Department of Natural History, Royal Ontario Museum; Nathan Lovejoy, Department of Biological Sciences; University of Toronto Scarborough taegan.perez@mail.utoronto.ca
The introduction of invasive species to ecosystems has been linked to biodiversity declines. Effective management of invasive species requires a good understanding of the species’ taxonomy, biology, and original distribution. Understanding the taxonomy of invasive species can be complicated when the species are members of hyper-diverse clades. In this study, we investigated the species identity of an invasive armoured catfish (Loricariidae) established in northeastern Costa Rica, and in the continental US. The taxonomy of Loricariidae is complex and subject to ongoing study, presenting challenges for species identification. We used an integrative approach to identification that combined DNA barcode sequencing, morphological analysis, and reference specimens and sequences from type localities. We determined that our samples document the presence of two non-native Hypostomus species: Hypostomus sp. Invasive (Costa Rica + Texas), and Hypostomus cf. plecostomus (Florida). In the case of Hypostomus sp. Invasive, analysis of our barcodes and those from the public barcode databases Genbank and BOLD, suggest that this species has also been introduced to localities in South America that are outside its native range. The taxonomy for this species has not been conclusively established; however, current data suggest it is Hypostomus niceforoi. |
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4. 09:15 Length–Weight relationship of Yellow Mojarra Caquetaia kraussii in the Cienaga Grande de Lorica, Colombia. Deimer D. Ramos-Pérez, Fishery Biology Research Laboratory-FBRL, Department of Aquatic Sciences. University of Cordoba; Juan J. Hernández-Correa, SEPEC; Jesús Vargas-González, Fishery Biology Research Laboratory-FBRL, Department of Aquatic Sciences. University of Cordoba; Ángel L. Martínez-González, Fishery Biology Research Laboratory-FBRL, Department of Aquatic Sciences. University of Cordoba; Glenys Tordecilla-Petro, Fishery Biology Research Laboratory-FBRL, Department of Aquatic Sciences. University of Cordoba; Charles W. Olaya-Nieto, Fishery Biology Research Laboratory-FBRL, Department of Aquatic Sciences. University of Cordoba; FredysF. Segura-Guevara*, Fishery Biology Research Laboratory-FBRL, Department of Aquatic Sciences. University of Cordoba colaya@correo.unicordoba.edu.co
The length-weight relationship (LWR) of Yellow Mojarra Caquetaia kraussii during an annual cycle between January and December 2017 in the Cienaga Grande de Lorica, Colombia, was estimated. LWR and condition factor were estimated with the equation TW =a*TL and k =TW/TL, respectively. 1167 individuals were collected, with sizes between 12.4-23.0 cm TL, weights between 34.3-199.2 g and mean length in the catch of 16.9 cm TL; where 409 were females, 500 males and 258 unsexed. Sexual dimorphism at size was found and 50.0% of the individuals showed sizes smaller than the minimum length in the catch established for the Sinu basin. LWR for both sexes was TW =0.031 (± 0.07) LT 2.79 (± 0.06), r =0.94, n =1167, with negative allometric growth coefficient and significant statistical differences; as well as the condition factor. Low correlation was observed between the condition factor and the Gonadosomatic Index of the species with the hydrological cycle of the Cienaga Grande de Lorica. The information analyzed suggests that the Yellow Mojarra is a small-sized fish, with sexual dimorphism at size, possible overfishing problem, negative allometric growth, low correlation between their body indices, the spawning season and the hydrological cycle of the Cienaga Grande de Lorica and possible overfishing problem. |