Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Conservation of Declining Populations02:07

Conservation of Declining Populations

Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.
What are Populations and Communities?00:30

What are Populations and Communities?

Overview
Conservation of Small Populations02:04

Conservation of Small Populations

Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Historical data reveal extirpation of foundation species and kelp forest community deborealization in a coastal hotspot.

Ecological applications : a publication of the Ecological Society of America·2026
Same author

Widespread ecological responses and cascading effects of the 2021 western North American heatwave.

Nature ecology & evolution·2026
Same author

Severe and widespread coral reef damage during the 2014-2017 Global Coral Bleaching Event.

Nature communications·2026
Same author

Algal Symbionts Indicate Heatwave Vulnerability in Corals From Hotspots but Not From Thermal Refugia.

Molecular ecology·2026
Same author

Only One Percent of Important Shark and Ray Areas in the Western Indian Ocean Are Fully Protected From Fishing Pressure.

Ecology and evolution·2026
Same author

Marine Heatwaves Transform Coral Symbioses With Enduring Effects.

Ecology letters·2025

Related Experiment Video

Updated: May 22, 2026

Reefshape: A System for the Efficient Collection and Automated Processing of Time-Series Underwater Photogrammetry Data for Benthic Habitat Monitoring
13:35

Reefshape: A System for the Efficient Collection and Automated Processing of Time-Series Underwater Photogrammetry Data for Benthic Habitat Monitoring

Published on: June 13, 2025

Re-creating missing population baselines for Pacific reef sharks.

Marc O Nadon1, Julia K Baum, Ivor D Williams

  • 1Joint Institute for Marine and Atmospheric Research, University of Hawaii, 1000 Pope Road, Honolulu, HI 96822, USA. marc.nadon@noaa.gov

Conservation Biology : the Journal of the Society for Conservation Biology
|April 28, 2012
PubMed
Summary

Shark populations on coral reefs have significantly declined, now at 3-10% of historical baseline levels. This study quantifies historical reef shark density, revealing a critical need for conservation efforts.

More Related Videos

Coral Reef Arks: An In Situ Mesocosm and Toolkit for Assembling Reef Communities
07:59

Coral Reef Arks: An In Situ Mesocosm and Toolkit for Assembling Reef Communities

Published on: January 6, 2023

Development of New Methods for Quantifying Fish Density Using Underwater Stereo-video Tools
09:32

Development of New Methods for Quantifying Fish Density Using Underwater Stereo-video Tools

Published on: November 20, 2017

Related Experiment Videos

Last Updated: May 22, 2026

Reefshape: A System for the Efficient Collection and Automated Processing of Time-Series Underwater Photogrammetry Data for Benthic Habitat Monitoring
13:35

Reefshape: A System for the Efficient Collection and Automated Processing of Time-Series Underwater Photogrammetry Data for Benthic Habitat Monitoring

Published on: June 13, 2025

Coral Reef Arks: An In Situ Mesocosm and Toolkit for Assembling Reef Communities
07:59

Coral Reef Arks: An In Situ Mesocosm and Toolkit for Assembling Reef Communities

Published on: January 6, 2023

Development of New Methods for Quantifying Fish Density Using Underwater Stereo-video Tools
09:32

Development of New Methods for Quantifying Fish Density Using Underwater Stereo-video Tools

Published on: November 20, 2017

Area of Science:

  • Marine Biology
  • Ecology
  • Conservation Science

Background:

  • Coral reef ecosystems historically supported abundant large predators like sharks.
  • Quantifying historical shark density is challenging due to limited time-series data.
  • Previous studies suggest negative associations between reef shark abundance and human populations.

Purpose of the Study:

  • To estimate baseline reef shark densities in the absence of human influence.
  • To analyze the relationship between reef shark abundance and human population density.
  • To assess the current decline in reef shark populations compared to historical levels.

Main Methods:

  • Analysis of 1607 towed-diver surveys across 46 reefs in the central-western Pacific.
  • Development of ecological models incorporating human population, primary productivity, sea surface temperature, reef area, and complexity.
  • Estimation of shark densities using these models to simulate baseline conditions.

Main Results:

  • Reef shark densities (gray reef, whitetip, and all reef sharks) positively correlated with primary productivity and sea surface temperature.
  • Shark densities significantly increased as human population density decreased.
  • Simulated baseline densities suggest current reef shark populations are only 3-10% of historical levels in studied areas.

Conclusions:

  • Human activities have drastically reduced reef shark populations on coral reefs.
  • Restoring historical shark densities requires mitigating human impact and addressing environmental factors.
  • Understanding baseline ecological conditions is crucial for effective marine conservation and management.