When we talk about protecting our oceans, one word comes up again and again: biodiversity. But what does it actually mean — and why is it so important?

What is Biodiversity?

Biodiversity refers to the variety of life on Earth — from tiny plankton drifting in the ocean, to seagrass meadows, coral reefs, fish, dolphins, seabirds, and whales.

It exists at three key levels:

• Species diversity – the number of different species
• Genetic diversity – variation within species
• Ecosystem diversity – the range of habitats like estuaries, reefs, and open ocean

In coastal regions like the Byron–Tweed Region Hope Spot, biodiversity is incredibly rich — where rivers meet the sea, creating a mosaic of habitats that support hundreds of interconnected species.

Why Biodiversity Matters in Marine Ecosystems

1. Healthy ecosystems depend on it

Every species plays a role. From seagrass stabilising sediments, to predators like dolphins and sharks maintaining balance — biodiversity keeps ecosystems functioning.

When biodiversity is high, ecosystems are:

• More stable
• More productive
• Better able to recover from disturbances 

2. Everything is connected

Marine ecosystems are deeply interconnected.

For example:

• Nutrients flow from rivers to the ocean
• Seagrass beds provide nursery habitat for fish
• Baitfish attract larger predators like dolphins and whales

A change in one part of the system can ripple across the entire ecosystem.

3. Biodiversity builds resilience

Oceans are facing increasing pressures — from climate change to pollution and coastal development.

Ecosystems with greater biodiversity are more resilient, meaning they can better:

• Adapt to warming waters
• Recover from extreme events
• Maintain essential functions

4. It supports people and communities

Healthy marine ecosystems support:

• Fisheries and food security
• Tourism and local economies
• Cultural values and connection to Country
• Recreation and wellbeing

Protecting biodiversity is not just about wildlife — it’s about people, place, and future generations.

What Threatens Marine Biodiversity?

Marine biodiversity is under increasing pressure from:

• Habitat loss and coastal development
• Pollution and runoff
• Marine debris and plastics
• Unsustainable fishing and wildlife disturbance
• Climate change
• Insufficient protection and marine sanctuary areas

These pressures often act together, creating cumulative impacts that increase vulnerability.

What Can We Do?

Protecting biodiversity starts with understanding it — and taking action.

You can help by:

• Participating in citizen science programs
• Reducing pollution and waste
• Respecting wildlife and marine habitats
• Supporting conservation initiatives
• Getting involved as an Ocean Champion

 Protect What You Love

Biodiversity is the foundation of ocean health.

When we protect it, we protect the systems that sustain life — including our own.

Together, we can ensure our oceans remain vibrant, resilient, and full of life for generations to come.

Image credits: Liz Hawkins

Protection and restoration of these coastal blue-carbon ecosystems is crucial due to the many benefits they provide to wildlife and local communities and economies. These benefits are associated with ecological functions and ecosystem services, which include habitat, food, medicine, water quality, storm surge protection, climate change mitigation and beauty.

Some of the main species that occur in saltmarsh are Juncus krausii (Sea Rush), Samolus repens (Creeping Brookweed), Suaeda australis (Austral Seablite), Sarcocornia quinqueflora (Samphire), and Sporobolus virginicus (Saltwater Couch).

Saltmarsh is listed as an Endangered Ecological Community (EEC) in NSW under the Threatened Species Conservation Act 1995.  Saltmarsh communities have declined by up to 80% hence they are at risk of extinction. In NSW, there has been a loss of 50% since the arrival of Europeans. A total of 31% of saltmarsh communities are protected in conservation reserves like National Parks. The other saltmarsh communities occur in populated coastal areas, and face threats from human activities.

Why We Need Saltmarsh

Saltmarsh is a vital habitat to ensure a healthy river system – the ecological community improves water quality, stabilises riverbanks, and is a habitat and food source for fish. It’s a critical buffer system between the fresh river water and salty ocean water, and one of few habitats that can survive the coastal salty soils. Along with mangroves, they protect our coast by reducing erosion and damage from storms. 

Bigger picture, saltmarsh and mangroves are hugely important for sequestration of carbon dioxide. They also support healthy fisheries, as a nursery and refuge for fish, shrimp, crabs and more. 

Threats

• Coastal development, which includes building roads, bridges, canals and marinas
• Poor water quality due to run-off from land clearing, overgrazing, stormwater and agriculture
• Grazing animals
• Weeds
• Pollution and accidental spills
• Climate change induced sea level rise
• Human use
• Illegal dumping of green waste
• Invasion by pest species
• Encroachment (from neighbouring properties) 

Ways You Can Help Saltmarsh

• Reducing your carbon footprint
• Buying sustainable and responsibly sourced seafood
• Joining coast care groups in your area
• Working to improve water quality
• Establishing and maintaining buffer zones between coastal habitats and urban developments in their proximities
• Prioritising the protection of areas where saltmarsh and other coastal habitats are likely to retreat with sea level rise
• Fencing along the intertidal zone to prevent access of livestock
• Assist with saltmarsh assessment and monitoring (Join Ozfish to monitor saltmarsh)
• Join a community cleanup 
• Avoid walking or driving on saltmarsh
• Join Coast Care or Land Care groups in weed removal and/or planting days

Learn More

Here’s a useful link for identification – Coastal Saltmarsh

How You Can Help

Join Ozfish to protect and improve the last remnants of saltmarsh on the Richmond River – Ozfish: Saving Our Saltmarsh

Threats
• Coastal development, which includes building roads, bridges, canals and marinas
• Poor water quality due to run-off from land clearing, overgrazing and agriculture
• Ports, dredging and any activity that physically damages seagrass or interferes with the conditions around seagrass meadows
• Boating, boat anchors and trampling
• Overfishing
• Pollution and accidental spills
• Climate change
• Human use

Ways You Can Help Seagrass Meadows
• Reducing your carbon footprint
• Buying sustainable and responsibly sourced seafood
• Joining coast care groups in your area
• Working to improve water quality
• Establishing and maintaining buffer zones between coastal habitats and urban developments in their proximities
• Prioritising the protection of areas where mangrove and other coastal habitats are likely to retreat with sea level rise
• Fencing along the intertidal zone to prevent access of livestock
• Creating protected areas of seagrass
• Reducing overfishing

Learn About The Different Seagrass Species

Threats

• Coastal development, which includes building roads, bridges, canals and marinas
• Coastal erosion affecting shorelines, estuaries and lakes
• Poor water quality due to run-off from land clearing, overgrazing and agriculture
• Pollution and accidental spills
• Climate change
• Human use

Ways You Can Help Mangroves

• Reducing your carbon footprint
• Buying sustainable and responsibly sourced seafood
• Joining coast care groups in your area
• Establishing and maintaining buffer zones between coastal habitats and urban developments in their proximities
• Prioritising the protection of areas where mangrove and other coastal habitats are likely to retreat with sea level rise
• Fencing along the intertidal zone to prevent access of livestock

Learn About The Different Mangrove Species