REVEALED: How healthy Gladstone's Harbour really is
A REPORT into the health of Gladstone's Harbour has raised new concerns about fishing pressure due to low male mud crab numbers.
The Gladstone Healthy Harbour Partnership's fourth report, released last night, is its most comprehensive yet with the addition of a mud crab indicator and new measures for coral and sediment.
The annual survey - which gave the environmental health of the harbour a C grade - found there were fewer decent sized male mud crabs than females, causing concern for fishing pressure within some areas of the harbour.
Mud crab health received an overall C-grade with very good health in the Narrows, Boat Creek and the Inner Harbour, but very poor results in the Calliope Estuary, Auckland Inlet and Rodds Bay.
"A high ratio of female to male crabs can indicate a high level of fishing in an area as only male crabs can be legally taken," the report said.
"It is suspected the ratio of male to female crabs caught in these zones reflect fishing pressure."
The GHHP recorded a 6.3 per cent incidence of rust spot on mud crabs across seven zones, substantially lower than 37 per cent in 2012.
Similarly to previous reports, water and sediment quality continued were the highest performers, scoring B and A respectively.
"The nutrient scores improved in 10 harbour zones from 2016-17 ... Turbidity scores improved in 12 harbour zones," the GHHP explained.
While coral cover was poor with a D rating, it was an improvement from last year's E rating.
It found the recovery of coral communities "is slow but ongoing" with the density and diversity of juvenile corals showing improvement in 2017, compared to 2015-16.
Minister for the Great Barrier Reef, Leanne Enoch, congratulated the partnership on the release of the fourth report card.
"The Queensland Government's investment towards this year's report card is part of our ongoing commitment to work with local communities, industry, research groups and business in the Gladstone region to ensure a sustainable harbour and a healthy Great Barrier Reef for future generations to enjoy.
Information and data used in the report card has been provided by scientific research organisations, universities and specialist consultants overseen by GHHP Independent Science Panel and the science team.
- Water quality: B
- Sediment quality: A
- Health of habitats: D
- Coral cover: D
- Seagrass: D
- Fish recruitment: B
- Mud crabs: C
- Social health: B
- Economic health: B
- Ratings range from very good (A) to very poor (E).