The dataset is composed of six tables containing environmental DNA (eDNA) and electrofishing data from American eel (Anguilla rostrata) surveys conducted on parts of the Mohawk River watershed and tributaries to the Hudson River in New York. The dataset includes (a) eDNA data from 36 sites in the Mohawk River watershed and adjacent areas including parts of the Eastern Erie Canal, Mohawk River, and tributaries that were sampled in spring 2021 and again in summer 2021,(b) paired eDNA/electrofishing data from 15 sites on tributaries to the Hudson River that were sampled between 2020 and 2021, and (c) model output of predicted American eel density from all sites in the Mohawk River watershed and adjacent areas where eDNA was detected. The table "MohawkHudsonEel_MohawkScreening_eDNAData" contains eDNA data from the 36 sites in the Mohawk River watershed, the table "MohawkHudsonEel_MohawkScreening_SiteData" contains supporting information on the 36 sites in the Mohawk River watershed, the table "MohawkHudsonEel_HudsonTribCalibration_LWData" contains the length and weight for all American eel captured during electrofishing surveys from the 15 sites on tributaries to the Hudson River, the table "MohawkHudsonEel_HudsonTribCalibration_eDNAData" contains eDNA data from the 15 sites on tributaries to the Hudson River, the table "MohawkHudsonEel_HudsonTribCalibration_SiteData" contains supporting information on the 15 sites on tributaries to the Hudson River including the dimensions of the reaches where electrofishing was conducted, and the table "MohawkHudsonEel_MohawkScreening_DensityEstimate" contains predicted density of American eel estimated from eDNA concentration using linear regression from all sites in the Mohawk River watershed and adjacent areas where eDNA was detected.

Data are abundance and body size (length) of juvenile salmon, forage fish, and other species captured with a lampara net in eelgrass and nearby unvegetated habitat on the Skagit River Delta monthly, April-September, 2008-2010, as well as vegetation status, water depth, temperature, salinity, and clarity for each fish netting event.

These data are related to surveys of eelgrass beds in Norma Bay, Izembek Lagoon, Alaska. The table provides eelgrass shoot lengths and density measurements from sampling in September 1987.

These data are related to surveys of eelgrass beds in Norma Bay, Izembek Lagoon, Alaska. The table provides eelgrass shoot lengths and density measurements from sampling in September 1987.

This dataset was designed for Environment and Climate Change Canada's (ECCC) National Environmental Emergencies Center (NEEC) for oil spill preparedness and response. The polygons from this layer come mainly from the coastal ecosystems geodatabase as part of the Mapping of coastal ecosystems of the Estuary and Gulf of St. Lawrence project. This layer represents semi-vegetated and vegetated zones of which eelgrass is the dominant vegetation. The study area includes all of the estuarine and maritime coasts of Quebec, with the exception of certain sectors, including most of the Lower North Shore and Anticosti Island, with the exception of villages of Kegaska, la Romaine, Chevery, Blanc-Sablon and Port-Menier. Some islands off the estuary and gulf coasts are part of the region covered, such as Île d'Orléans, Isle-aux-Coudres, Île Verte and Île Bonaventure. The Mapping of coastal ecosystems of the Estuary and Gulf of St. Lawrence was carried out jointly by the Laboratory for Dynamics and Integrated Coastal Zone Management (LDGIZC) of the University of Quebec at Rimouski as part of the Coastal Resilience Project (https: //ldgizc.uqar.ca/Web/projets/projet-resilience-cotiere) funded by the MELCC; and by the Fisheries and Oceans Canada team, as part of its Integrated marine response planning (IMRP) component of the Oceans Protection Plan (OPP), with the objective of updating the Marine Oil Spill Preparedness and Response Regime of Canada. The master geodatabase of coastal ecosystems is hosted and distributed by UQAR on their SIGEC-Web mapping platform: https://ldgizc.uqar.ca/Web/sigecweb The characterization of eelgrass beds was mainly carried out using photo-interpretation of RVBI aerial photos acquired by DFO (2015-2020) and oblique photos taken by helicopter by UQAR in 2017. This dataset also includes the information from validation stations visited by UQAR (2018-2020). Data from sampling stations, carried out aboard small boats during DFO field campaigns (2017-2021), were also used to validate and refine the photo-interpretation. This dataset also includes eelgrass beds characterized in the Basse-Côte-Nord (MRC Le Golfe-de-Saint-Laurent) by the Agence Mamu Innu Kaikusseht (AMIK) as part of the project ''Involvement of Innu communities in the protection of species at risk and their habitats 2010-2011''. These data were produced during aerial overflights at low altitude (200m and 400m) of the foreshore, as 2 observers circumscribed and documented the covering of eelgrass beds. Credits © UQAR-MPO-AMIK (2023, Laboratoire de dynamique et de gestion intégrée des zones côtières, Pêches et Océans Canada, Agence Mamu Innu Kaikusseht) Provencher-Nolet, L., Paquette, L., Pitre, L.D., Grégoire, B. and Desjardins, C. 2024. Cartographie des macrophytes estuariens et marins du Québec. Rapp. Tech. Can. Sci. halieut. Aquat. 3617 : v + 99 p. Grégoire, B., Pitre, L.D., Provencher-Nolet, L., Paquette, L. and Desjardins, C. 2024. Distribution d’organismes marins de la zone côtière peu profonde du Québec recensés par imagerie sous-marine de 2017 à 2021. Rapp. tech. can. sci. halieut. aquat. 3616 : v + 78 p. Grégoire, B. 2022. Biodiversité du relevé côtier Planification pour une intervention environnementale intégrée dans l’estuaire et le golfe du Saint-Laurent (2017–2021). Observatoire global du Saint-Laurent. [Jeu de données] Nadeau, V., Le Breton, S. 2011. Inventaire aérien des herbiers de zostère de la Basse-Côte-Nord du Golfe du Saint-Laurent. Agence Mamu Innu Kaikusseht. 25 p. Jobin, A., Marquis, G., Provencher-Nolet, L., Gabaj Castrillo. M. J., Trubiano C., Drouet, M., Eustache-Létourneau, D., Drejza, S. Fraser, C. Marie, G. et P. Bernatchez (2021) Cartographie des écosystèmes côtiers du Québec maritime — Rapport méthodologique. Chaire de recherche en géoscience côtière, Laboratoire de dynamique et de gestion intégrée des zones côtières, Université du Québec à Rimouski. Rapport remis au ministère de l’Environnement et de la Lutte contre les

This dataset includes biological variables showing surf smelt spawning presence, geological variables describing beach composition, and sample locations using RTK-GPS. This field data was also used to run the Sea Level Affecting Marshes Model (SLAMM; Warren Pinnacle Consulting, Inc., Warren, Vt)) to predict the changes to beaches over time, and under different sea level rise scenarios. Field sampling took place on the northern part of Bainbridge Island, Puget Sound, Washington during summer and fall of 2010.

This dataset includes biological variables showing surf smelt spawning presence, geological variables describing beach composition, and sample locations using RTK-GPS. This field data was also used to run the Sea Level Affecting Marshes Model (SLAMM; Warren Pinnacle Consulting, Inc., Warren, Vt)) to predict the changes to beaches over time, and under different sea level rise scenarios. Field sampling took place on the northern part of Bainbridge Island, Puget Sound, Washington during summer and fall of 2010.

This dataset includes metrics of eelgrass size, cover, and biomass from field sites along the Atlantic coast of Nova Scotia, Canada. Field sites were located across a gradient of environmental conditions, and field sampling was conducted in July to August 2022. Eelgrass percent cover, shoot density, and plants were sampled at 10 haphazardly distributed sampling stations within each eelgrass bed at approximately the same depth. Stations were ~10m apart and at least 2m from any eelgrass-bare interface. At each sampling station eelgrass leaves in a 0.5 x 0.5m quadrat were photographed for later computer image analysis to determine percent cover. The number of shoots were then counted in a 0.25 x 0.25m quadrat, and 3 vegetative shoots were collected. Shoots were measured for leaf length, width, and weight in the laboratory. These data were used to determine allometric and cover-biomass relationships for use in non-destructive estimation of bed biomass. Cite this data as: Wong, M.C., & Thomson, J. A. Data of eelgrass (Zostera marina) plant size (length, width), cover, and biomass from the Atlantic Coast of Nova Scotia. Published: February 2025. Coastal Ecosystems Science Division, Maritimes Region, Fisheries and Oceans Canada, Dartmouth NS. For additional information please see: Thomson, J. A., Vercaemer, B., & Wong, M. C. (2025). Non-destructive biomass estimation for eelgrass (Zostera marina): Allometric and percent cover-biomass relationships vary with environmental conditions. Aquatic Botany, 198, 103853. https://doi.org/10.1016/j.aquabot.2024.103853

This dataset includes metrics of eelgrass traits related to bed structure, morphology, and physiology from field sites along the Atlantic coast of Nova Scotia, Canada. Field sites were located across a gradient of temperature and light conditions. Sampling was conducted in July to August, in 2017, 2021, and 2022. Seagrass density and plants were sampled at 10 haphazardly distributed sampling stations within each seagrass bed at approximately the same depth. Stations were ~10m apart and at least 2m from any seagrass-bare interface. Quadrats were used to determine vegetative and reproductive shoot density. Three plants from each sampling station were collected and processed in the laboratory for length and width leaf 3, number leaves per shoot, rhizome width, rhizome water soluble carbohydrates, and total leaf chlorophyll. Also included in this data temperature and light metric that summarize temperature and light conditions during the summer period. Cite this data as: Wong, M.C., Dowd, M. Data of eelgrass (Zostera marina) traits from the Atlantic Coast of Nova Scotia. Published: February 2025. Coastal Ecosystems Science Division, Maritimes Region, Fisheries and Oceans Canada, Dartmouth NS. For additional information please see: Wong, M.C., Dowd, M. Eelgrass (Zostera marina) Trait Variation Across Varying Temperature-Light Regimes. Estuaries and Coasts 48, 13 (2025). https://doi.org/10.1007/s12237-024-01439-3

The layer presents the information on the distribution of eelgrass (Zostera marina) beds in James Bay, Chaleur Bay, Estuary and Gulf of St. Lawrence according to a literature review of documents produced between 1987 and 2009. Additional Information Eelgrass's inventory was produced according to a literature review of the following documents: Calderón, I. 1996. Caractérisation de la végétation et de la faune ichtyenne de la baie de Sept-Îles. Document réalisé par la Corporation de protection de l'environnement de Sept-Îles pour Pêches et Océans Canada. 26p. + 5 annexes. Comité côtier Les Escoumins à la Rivière Betsiamites. 2004. Inventaire de localisation des bancs de zostère marine dans la zone côtière Les Escoumins à la rivière Betsiamites. 9 p. Comité ZIP Côte-Nord du Golfe. 2001. Inventaire du potentiel côtier et marin de la Basse-Côte-Nord. Version préliminaire de rapport sous forme de CD-ROM, Sept-Îles, mars 2001. Comité ZIP de la rive nord de l’estuaire. 2008. Guide d’intervention en matière de protection et de mise en valeur des habitats littoraux d’intérêt de la rive nord de l’estuaire maritime (fiches 14 à 20). 8 p. + 7 fiches + annexe. Conseil Régional de l’Environnement Gaspésie et des Îles-de-la-Madeleine (2004). Inventaire et étude des bancs de zostère marine sur le territoire couvert par les comités de gestion intégrée de la zone côtière de l’Est du Québec. CONSORTIUM GAUTHIER & GUILLEMETTE - G.R.E.B.E. 1992. Description et cartographie des habitats côtiers de la Baie de Hannah jusqu'à la rivière au Castor. Rapport présenté à Hydro-Québec, Complexe Nottaway-Broadback-Rupert (NBR), Vol. 2, Annexe cartographique. Giguère, M., C. Duluc, S. Brulotte, F. Hazel, S. Pereira et M. Gaudet. 2006. Inventaire d’une population d'huître américaine (Crassostrea virginica) dans le Bassin aux Huîtres aux Îles-de-la-Madeleine en 2005. Rapport manuscrit. vi + 21 p. Grant, C. et L. Provencher, 2007. Caractérisation de l’habitat et de la faune des herbiers de Zostera marina (L.) de la péninsule de Manicouagan (Québec). Rapp. tech. can. sci. halieut. aquat. 2772 : viii + 65 p. Groupe Environnement Littoral. 1992. Complexe NBR. La zostère marine. Rapport présenté à la vice-présidence Environnement d'Hydro-Québec. 9 p. + 2 cartes. Harvey, C. et D. Brouard. 1992. Étude exploratoire du barachois de Chandler: aspects biophysiques et contamination. Rapport présenté à Environnement Canada, Direction de la protection de l'environnement région du Québec. 39 p. et annexes. Hazel, François, 2002. Données de terrain prises par F. Hazel, Septembre 2002. Ellefsen, H.-F. 2009. Communication personnelle de Hans-Frédéric Ellefsen (MPO). Jacquaz et coll. 1990. Étude biophysique de l'habitat du poisson de quatre barachois de la baie des Chaleurs. Kedney, G. et P. Kaltenback. 1996. Acquisition de connaissances et mise en valeur des habitats du banc de Portneuf. Document réalisé par la firme Pro Faune pour le Comité touristique de Rivière-Portneuf. 50 pages et 5 annexes. Lalumière, R. 1987. Répartition de la zostère marine (Zostera marina) sur la côte est de la baie James; été 1987. Rapport produit par Gilles Shooner et Associés inc. pour la Société d’énergie de la Baie James. 30 p. et annexes. Lalumière, R., L. Belzile et C. Lemieux. 1992. Étude de la zostère marine le long de la côte nord-est de la baie James (été 1991). Rapport présenté au Service écologie de la SEBJ. 31 p. + carte. Leblanc, J. 2002. Communication personnelle de Judith Leblanc (MPO). Lemieux, C. 1995. Acquisition de connaissances des habitats côtiers dans la région de Rimouski (1995). Rapport du Groupe-Conseil GENIVAR présenté au Ministère des Pêches et des Océans du Canada, Division de la Gestion de l’Habitat du Poisson, 52 pages + 2 annexes. Lemieux, C. et R. Lalumière. 1995. Acquisition de connaissances des habitats côtiers du barachois de Saint-Omer. Rap. du Groupe conseil Genivar inc. pour la DGHP, MPO, 44 pages + 3 ann. Martel, Marie-Claude, Lizon Provencher, Cindy Grant,