Recording-2026-02-23T21:29:58.088Z

Class Overview

  • Instructor Introduction

    • Welcome to students, introduction to the research center in New Caledonia.
    • Students learning from peers working in Fiji and New Caledonia.

  • Unit Structure

    • Class: Society in the Oceans 103
    • Focus on sociology of the oceans.
    • Recap of previous units:
    • Unit 1: Ocean crisis from biophysical and social perspectives.
    • Unit 2: Malthusian argument debate:
      • Proponents: Garrett Hardin: "Too many mouths to feed."
      • Critiques by Eleanor Ostrom and other social scientists.
    • Unit 3: Case studies:
      • Salish Sea, dam removal discussion with David Montgomery.

  • Unit 4 Objectives

    • Discuss the tropics and coral reefs.
    • Importance of coral reefs as biodiverse ecosystems.
    • Role of small scale fisheries in food security.
    • Influence of social conditions and historical legacies on coastal degradation.
    • Next class: Eddie Ellis will discuss solutions.

Understanding the Tropics

  • Defining the Tropics

    • Located between two latitudes: 27.5° North (Tropic of Cancer) and 27.5° South (Tropic of Capricorn).
    • Characterized by high sunlight exposure, affecting wind and current patterns.

  • Sunlight and Coral Reefs

    • Coral reefs require sunlight for photosynthesis, influencing their location in shallow waters.

Coral Ecosystem

  • Introduction to Corals

    • Definition: Hermatypic corals create calcium carbonate structures (homes).
    • Temperature tolerance: Optimal range is 18°C to 27°C (64°F to 81°F).
    • Impact of temperature anomalies: Prolonged temperatures above 27°C lead to coral bleaching.

  • Water Quality

    • Oligotrophic vs Eutrophic:
    • Oligotrophic: Low nutrient levels, ideal for coral health.
    • Eutrophic: Excess nutrients lead to algal growth, smothering corals.

Coral Reefs and Biodiversity

  • Types of Coral Reefs

    • Fringing Reefs: Adjacent to the shore.
    • Barrier Reefs: Separate from the shore by deeper lagoons (e.g., Great Barrier Reef, New Caledonia).
    • Atolls: Circular coral formations remaining after island erosion.

  • Coral Structure

    • Corals are colonial, comprised of polyps.
    • Symbiotic relationship: Corals house zooxanthellae algae providing energy through photosynthesis, while benefiting from nutrient excretion.

Coral Reproductive Strategies

  • Asexual Reproduction

    • Fragments can develop into new colonies (e.g., Acropora species).

  • Sexual Reproduction

    • Corals spawn in synchrony with lunar cycles; fertilized eggs develop into planulae.

Reef Zones and Dynamics

  • Reef Structure
    • The seagrass zone, reef flat, and crest area characterized by biodiversity and productivity.

Cultural Perspectives on Coral Reefs

  • Integration of Knowledge
    • Importance of local and traditional knowledge in coral reef management.
    • Emphasis on stories from the Pacific Indigenous communities, like Kanak people's relationship with the environment.

Projects and Presentations