Operation Crayweed - Lurline Bay

Restoration Project

Operation Crayweed - Lurline Bay

Restoration Objective:

Operation Crayweed aims at restoring crayweed in Lurline Bay.

Site Selection Criteria:

In November 2023, a new restoration site was set up within Lurline Bay (~4 m depth). This involved installing 21 temporary mats that were drilled into the rock to host donor crayweeds and facilitate restoration. The size of one mat is 600 x 352 mm. The new site selected is a reef located on the edge of two dominant habitats: 1) an expansive urchin barren, absent of macroalgae and 2) a shallow bed of existing macroalgae (characterised by turf algae, sargassum and golden kelp, Ecklonia radiata). This resembles similar sites where extant crayweed forests are generally found north and south of Sydney. Crayweed was transplanted here in November 2023 and topped up in September 2024.

Cause Of Decline:

The high volumes of poorly treated sewage that were pumped directly onto Sydney’s beaches and bays before the 1990s likely caused this decline.

Key Reasons For Decline:

Water Pollution

Organisation:

The aim of OPERATION CRAYWEED is to bring crayweed back to reefs where it once flourished and to re-establish this essential habitat and food source for Sydney’s coastal marine biodiversity.

Scientists at Operation Crayweed have already developed a successful method to create crayweed forests on reefs where they were once dominant, by transplanting healthy, fertile adults from existing populations and attaching them to deforested rocks using biodegradable mesh drilled into the bottom. There, they survive, they thrive and they start having sex - a lot of sex.

Site Observations: