These data are is part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. Specifically, these data describe sea otter (Enhydra lutris) aerial survey observations from the waters around Kenai Fjords National Park between 2002 and 2016. Sea otters are a keystone predator, well known for structuring the nearshore marine ecosystem through their consumption of invertebrate prey. The dataset consists of 3 comma delimited files exported from Microsoft Excel. The data consists of 1. Strip transect counts, 2. Intensive Search Unit (ISU) counts, and 3. Transect coordinates. For each aerial survey, a pilot flew an airplane at an altitude of 91m over pre-determined transects while an observer searched on one side of the plane and recorded sea otter group counts and locations. Sea otters observed within 400 m of each transect were later used to estimate abundance. Sea otters sighted beyond the confines of designated transect swaths were also counted and mapped, time permitting. To estimate the number of sea otters in small groups (<20) not detected along transect swaths (e.g., due to diving behavior or the presence of kelp canopy), 400m diameter circles (i.e. ISUs) were searched intensively by periodically flying 5 concentric circles around an initiating group. These ISUs were distributed throughout the survey area in an attempt to accurately represent the full range of observation conditions encountered during the survey. When large groups of sea otters (≥20) were sighted on transect, they were circled until a complete count was made.

These data are part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. Specifically, these data describe sea otter (Enhydra lutris) aerial survey observations from the waters around Katmai National Park and Preserve from surveys conducted in 2008, 2012, 2015, and 2018. Sea otters are a keystone predator, well known for structuring the nearshore marine ecosystem through their consumption of invertebrate prey. The dataset consists of 3 comma-delimited files (CSV) exported from Microsoft Excel. The data consists of (1) Strip transect counts, (2) Intensive Search Unit (ISU) counts, and (3) Transect coordinates. For each aerial survey, a pilot flew an airplane at an altitude of 91 meters over pre-determined transects while an observer searched on one side of the plane and recorded sea otter group counts and locations. Sea otters observed within 400 meters of each transect were later used to estimate abundance. Sea otters sighted beyond the confines of designated transect swaths were also counted and mapped, time permitting. To estimate the number of sea otters in small groups (<20) not detected along transect swaths (e.g., due to diving behavior or the presence of kelp canopy), 400 meter diameter circles (i.e. ISUs) were searched intensively by periodically flying 5 concentric circles around an initiating group. These ISUs were distributed throughout the survey area in an attempt to accurately represent the full range of observation conditions encountered during the survey. When large groups of sea otters (>=20) were sighted on transect, they were circled until a complete count was made. Data are presented as three CSV files: KATM sea otter strip transect counts in dd.csv, KATM sea otter ISU counts.csv, KATM sea otter survey transect coordinates in dd.csv

These data are part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. Specifically, these data describe sea otter (Enhydra lutris) aerial survey observations from the waters around Katmai National Park and Preserve from surveys conducted in 2008, 2012, 2015, and 2018. Sea otters are a keystone predator, well known for structuring the nearshore marine ecosystem through their consumption of invertebrate prey. The dataset consists of 3 comma-delimited files (CSV) exported from Microsoft Excel. The data consists of (1) Strip transect counts, (2) Intensive Search Unit (ISU) counts, and (3) Transect coordinates. For each aerial survey, a pilot flew an airplane at an altitude of 91 meters over pre-determined transects while an observer searched on one side of the plane and recorded sea otter group counts and locations. Sea otters observed within 400 meters of each transect were later used to estimate abundance. Sea otters sighted beyond the confines of designated transect swaths were also counted and mapped, time permitting. To estimate the number of sea otters in small groups (<20) not detected along transect swaths (e.g., due to diving behavior or the presence of kelp canopy), 400 meter diameter circles (i.e. ISUs) were searched intensively by periodically flying 5 concentric circles around an initiating group. These ISUs were distributed throughout the survey area in an attempt to accurately represent the full range of observation conditions encountered during the survey. When large groups of sea otters (>=20) were sighted on transect, they were circled until a complete count was made. Data are presented as three CSV files: KATM sea otter strip transect counts in dd.csv, KATM sea otter ISU counts.csv, KATM sea otter survey transect coordinates in dd.csv

This data is part of the Gulf Watch Alaska (GWA) long term monitoring program, benthic monitoring component and a seasonal diet study in Kenai Fjords National Park. The dataset is a comma separated file exported from a Microsoft Access database. The data consists of observations made of foraging sea otters (Enhydra lutris). Observers used Questar field model spotting scopes and binoculars to identify prey. Date, local time, dive duration, success, prey type, prey size, prey number, handling time and surface time are all recorded. Sites are in Alaska and include locations in Katmai National Park and Preserve, Kenai Fjords National Park and Prince William Sound. This data in this file were collected 2012-2016.

This data is part of the Gulf Watch Alaska (GWA) long term monitoring program, benthic monitoring component and a seasonal diet study in Kenai Fjords National Park. The dataset is a comma separated file exported from a Microsoft Access database. The data consists of observations made of foraging sea otters (Enhydra lutris). Observers used Questar field model spotting scopes and binoculars to identify prey. Date, local time, dive duration, success, prey type, prey size, prey number, handling time and surface time are all recorded. Sites are in Alaska and include locations in Katmai National Park and Preserve, Kenai Fjords National Park and Prince William Sound. This data in this file were collected 2012-2016.

This dataset consists of three tables related to abundance and distribution of northern sea otters (Enhydra lutris kenyoni) in Southeast Alaska, based on data collected during a series of population-wide aerial surveys. The dataset consists of: (1) sea otter counts along strip transects, (2) sea otter counts in Intensive Search Unit (ISU) within the transects, and (3) Transect coordinates.

The data package "Sea Otter Aerial Survey Data from Southeast Alaska, 2002-2003" provides raw data for examining abundance and distribution of northern sea otters (Enhydra lutris kenyoni) in Southeast Alaska, based on data collected during a series of population-wide aerial surveys. The USGS aerial sea otter surveys have been completed multiple times using consistent methodology involving aerial-based counts. The surveys provide data and a population estimate that federal and state management agencies use for decision making and planning additional research. This data package includes a series of files with the raw digital data that was used for population estimates and population modeling found in related manuscripts.

This dataset consists of three tables related to abundance and distribution of northern sea otters (Enhydra lutris kenyoni) in lower Cook Inlet and the outer Kenai Peninsula, Alaska, based on data collected during a series of aerial surveys from May-Aug 2002. The dataset consists of: (1) sea otter counts along strip transects, (2) sea otter counts in Intensive Search Unit (ISU) within the transects, and (3) transect coordinates. **NOTE: 2002 data from survey sections in Kenai Fjords National Park are also included in another USGS data release available at https://doi.org/10.5066/F7CJ8BN7

This dataset consists of three tables related to abundance and distribution of northern sea otters (Enhydra lutris kenyoni) in lower Cook Inlet and the outer Kenai Peninsula, Alaska, based on data collected during a series of aerial surveys from May-Aug 2002. The dataset consists of: (1) sea otter counts along strip transects, (2) sea otter counts in Intensive Search Unit (ISU) within the transects, and (3) transect coordinates. **NOTE: 2002 data from survey sections in Kenai Fjords National Park are also included in another USGS data release available at https://doi.org/10.5066/F7CJ8BN7

This dataset consists of three tables related to abundance and distribution of northern sea otters (Enhydra lutris kenyoni) near the outer Kenai Peninsula, Alaska, based on data collected during a series of population-wide aerial surveys in June 2019. The dataset consists of: (1) sea otter counts along strip transects, (2) sea otter counts in Intensive Search Unit (ISU) within the transects, and (3) Transect coordinates.