Distribution and Demographics of Marine Mammals in SOCAL Through Photo-Identification, Genetics, and Satellite Telemetry

2014 ◽  
Author(s):  
Erin A. Falcone ◽  
Gregory S. Schorr
Keyword(s):  
Marine Mammals ◽  
Satellite Telemetry ◽  
Photo Identification

scholarly journals Age determination of common bottlenose dolphins (Tursiops truncatus) using dental radiography pulp:tooth area ratio measurements

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242273
Author(s):  
Jean M. Herrman ◽  
Jeanine S. Morey ◽  
Ryan Takeshita ◽  
Sylvain De Guise ◽  
Randall S. Wells ◽  
...  
Keyword(s):  
Life Histories ◽  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Age Determination ◽  
Area Ratio ◽  
Dental Radiography ◽  
Ratio Method ◽  
Data Sets ◽  
Photo Identification ◽  
Development And Validation

Age is an important parameter to better understand wildlife populations, and is especially relevant for interpreting data for fecundity, health, and survival assessments. Estimating ages for marine mammals presents a particular challenge due to the environment they inhabit: accessibility is limited and, when temporarily restrained for assessment, the window of opportunity for data collection is relatively short. For wild dolphins, researchers have described a variety of age-determination techniques, but the gold-standard relies upon photo-identification to establish individual observational life histories from birth. However, there are few populations with such long-term data sets, therefore alternative techniques for age estimation are required for individual animals without a known birth period. While there are a variety of methods to estimate ages, each involves some combination of drawbacks, including a lack of precision across all ages, weeks-to-months of analysis time, logistical concerns for field applications, and/or novel techniques still in early development and validation. Here, we describe a non-invasive field technique to determine the age of small cetaceans using periapical dental radiography and subsequent measurement of pulp:tooth area ratios. The technique has been successfully applied for bottlenose dolphins briefly restrained during capture-release heath assessments in various locations in the Gulf of Mexico. Based on our comparisons of dental radiography data to life history ages, the pulp:tooth area ratio method can reliably provide same-day estimates for ages of dolphins up to about 10 years old.

scholarly journals Site Fidelity and Residency of Tursiops truncatus off the Aragua Coast, Venezuela-First Records of Long Residency

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
S. Cobarrubia-Russo ◽  
Sawyer I. ◽  
M. Gómez-Alceste ◽  
A. Molero-Lizarraga
Keyword(s):  
Bottlenose Dolphin ◽  
Marine Mammals ◽  
Site Fidelity ◽  
Marine Protected Area ◽  
Extended Period ◽  
Comprehensive Analysis ◽  
Agglomerative Hierarchical Clustering ◽  
Photo Identification ◽  
Whale Sharks ◽  
First Time

This study represents the first comprehensive analysis of the residency patterns of a coastal population of bottlenose dolphin off the coast of Aragua, Venezuela, over a multi-year period. Using photo-identification, the most recent study (2019-2020) identified 56 individuals with the time between encounters from one to 344 days between the first and last sighting. Site Fidelity (SF) and Residence (RES) indices were calculated and Agglomerative Hierarchical Clustering (AHC) modeling was performed, with three patterns of residence obtained: resident (25%), semiresident (17.86%) and transient (57.14%). These results were contrasted with remodeled data from a previous study (2006-2007), showing similar patterns: resident (24.44%), semi-resident (28.89%) and transient (46.67%). Importantly, two individuals were found to have been resident over the extended period. A breeding female sighted for the first time in 2004 and again in 2020 (16 years) and the other from 2005 to 2020 (15 years). This region is an important area for marine mammals, known to support a resident reproductive population over many years, as well seabirds, sea turtles, whale sharks and fishermen. We recommend that consideration be given to designating the waters as a Marine Protected Area to safeguard the existing population and provide benefit to the surrounding marine environment.

RoI detection and segmentation algorithms for marine mammals photo-identification

2020 ◽  
Vol 56 ◽  
pp. 101038 ◽  
Author(s):  
Débora Pollicelli ◽  
Mariano Coscarella ◽  
Claudio Delrieux
Keyword(s):  
Marine Mammals ◽  
Photo Identification ◽  
Segmentation Algorithms

scholarly journals Estimating the Abundance of Marine Mammal Populations

2021 ◽  
Vol 8 ◽  
Author(s):  
Philip S. Hammond ◽  
Tessa B. Francis ◽  
Dennis Heinemann ◽  
Kristy J. Long ◽  
Jeffrey E. Moore ◽  
...  
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Abundance Estimation ◽  
Primary Methods ◽  
Main Method ◽  
Entry Level ◽  
Photo Identification ◽  
Data Collection And Analysis ◽  
Key Issues ◽  
Conservation Assessments

Motivated by the need to estimate the abundance of marine mammal populations to inform conservation assessments, especially relating to fishery bycatch, this paper provides background on abundance estimation and reviews the various methods available for pinnipeds, cetaceans and sirenians. We first give an “entry-level” introduction to abundance estimation, including fundamental concepts and the importance of recognizing sources of bias and obtaining a measure of precision. Each of the primary methods available to estimate abundance of marine mammals is then described, including data collection and analysis, common challenges in implementation, and the assumptions made, violation of which can lead to bias. The main method for estimating pinniped abundance is extrapolation of counts of animals (pups or all-ages) on land or ice to the whole population. Cetacean and sirenian abundance is primarily estimated from transect surveys conducted from ships, small boats or aircraft. If individuals of a species can be recognized from natural markings, mark-recapture analysis of photo-identification data can be used to estimate the number of animals using the study area. Throughout, we cite example studies that illustrate the methods described. To estimate the abundance of a marine mammal population, key issues include: defining the population to be estimated, considering candidate methods based on strengths and weaknesses in relation to a range of logistical and practical issues, being aware of the resources required to collect and analyze the data, and understanding the assumptions made. We conclude with a discussion of some practical issues, given the various challenges that arise during implementation.

scholarly journals SEALNET: Facial recognition software for ecological studies of harbor seals

2022 ◽  
Author(s):  
Zachary Birenbaum ◽  
Hieu Do ◽  
Lauren Horstmeyer ◽  
Hailey Orff ◽  
Krista Ingram ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Facial Recognition ◽  
Image Data ◽  
Harbor Seals ◽  
Closed Set ◽  
Photo Identification ◽  
Bay Area ◽  
Open Set ◽  
Coastal Species ◽  
Behavioral Studies

Methods for long-term monitoring of coastal species such as harbor seals, are often costly, time-consuming, and highly invasive, underscoring the need for improved techniques for data collection and analysis. Here, we propose the use of automated facial recognition technology for identification of individual seals and demonstrate its utility in ecological and population studies. We created a software package, SealNet, that automates photo identification of seals, using a graphical user interface (GUI) software to identify, align and chip seal faces from photographs and a deep convolutional neural network (CNN) suitable for small datasets (e.g., 100 seals with five photos per seal). We piloted the SealNet technology with a population of harbor seals located within Casco Bay on the coast of Maine, USA. Across two-years of sampling, 2019 and 2020, at seven haul-out sites in Middle Bay, we processed 1529 images representing 408 individual seals and achieved 88% (93%) rank-1 accuracy in closed set (open set) seal identification. We identified four seals that were photographed in both years at neighboring haul-out sites, suggesting that some harbor seals exhibit site fidelity within local bays across years, and that there may be evidence of spatial connectivity among haul-out sites. Using capture-mark-recapture (CMR) calculations, we obtained a rough preliminary population estimate of 4386 seals in the Middle Bay area. SealNet software outperformed a similar face recognition method developed for primates, PrimNet, in identifying seals following training on our seal dataset. The ease and wealth of image data that can be processed using SealNet software contributes a vital tool for ecological and behavioral studies of marine mammals in the emerging field of conservation technology.

An affine invariant curve matching method for photo-identification of marine mammals

2005 ◽  
Vol 38 (1) ◽  
pp. 125-132 ◽  
Author(s):  
C. Gope ◽  
N. Kehtarnavaz ◽  
G. Hillman ◽  
B. Würsig
Keyword(s):  
Marine Mammals ◽  
Invariant Curve ◽  
Curve Matching ◽  
Affine Invariant ◽  
Matching Method ◽  
Photo Identification

scholarly journals ECOLOGICAL AND ENVIRONMENTAL-PHYSIOLOGICAL RESEARCHES OF PINNIPEDS OF BARENTS, WHITE AND KARA SEAS IN 2015–2019

2020 ◽  
Vol 11 (4) ◽  
pp. 198-214
Author(s):  
N.N. Kavtsevich ◽  
◽  
I.A. Erokhina ◽  
V.N. Svetochev ◽  
O.N. Svetocheva ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Satellite Telemetry ◽  
Ringed Seal ◽  
Harp Seal ◽  
The Arctic ◽  
Bearded Seal ◽  
Arctic Seas ◽  
Physiological Studies

A brief review of the most significant ecological and environmental-physiological studies of three species of true seals living in the arctic seas is presented. The results were obtained on the basis of the analysis of materials from the expeditions of Marine Mammals Laboratory in the Barents, White and Kara seas in 2015–2019. Special attention is paid to the application of satellite telemetry as well as hematological,biochemical, cytochemical methods in the study of harp seal, ringed seal, bearded seal.

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