Terry Hughes: Dredging on the Great Barrier Reef

Coal mining and natural gas extraction (fracking) in Queensland, Australia are expanding rapidly. Apart from the enormous additional CO2 emissions, the expansion of huge ports and dumping of dredge spoil within the Great Barrier Reef (GBR) World Heritage Area have prompted UNESCO to consider including the GBR on their list of “World Heritage Areas in Danger”. The Australian Federal government and the State of Queensland earn billions of dollars in royalties from mining and they are now fast-tracking new mega-coal mines and the largest coal and gas ports in the world. These officials claim that dredging and dumping >100 million cubic meters of sediment will cause no significant damage to the environment.

However, two new scientific studies from James Cook University prove that dredging is a major threat to marine ecosystems, including coral reefs. A recent study by Pollock et al. shows that dredging-associated sedimentation and turbidity dramatically increase coral disease levels on nearby reefs. Essentially, corals get sick more often when they are stressed by reduced light levels and sedimentation (http://dx.plos.org/10.1371/journal.pone.0102498). A separate study by Burns examines the dispersal of fine particles, and shows that hydrocarbons from coal have already dispersed across the width of the GBR, and are approaching international benchmarks for toxicity in suspended sediments and on the benthos (http://dx.doi.org/10.1016/j.ecss.2014.04.001).
Together these benchmark studies prove that dredging is a major threat to the Great Barrier Reef. I encourage you to read them.
Yesterday, Australia became the first country to repeal legislation that curbs CO2 emissions.

Paper citations:
Pollock FJ, Lamb JB, Field SN, Heron SF, Schaffelke B, Shedrawi G, Bourne DG, Willis BL (2014) Sediment and turbidity associated with offshore dredging increase coral disease prevalence on nearby reefs. PLoS ONE 9(7): e102498. doi:10.1371/journal.pone.0102498
Burns KA (2014) PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities. Estuarine, Coastal and Shelf Science 144:39-45. http://dx.doi.org/10.1016/j.ecss.2014.04.001

Prof. Terry Hughes FAA
Director, ARC Centre of Excellence for Coral Reef Studies
James Cook University
Townsville, QLD 4811, AUSTRALIA
Fax: 61 (0) 4781-6722
tel: 61 (0)7-4781-4000

Special thanks to Coral-list

Cecilia D-Angelo, Jorg Wiedenmann: Impacts of nutrient enrichment on coral reefs: new perspectives and implications for coastal management and reef survival


Open Access view full pdf: Impacts of Nutrient Enrichment

• Nutrient enrichment negatively affects coral physiology and ecosystem functioning.
• Integrative model of reef survival in dependence of direct and indirect nutrient effects.
• Coastal run-off-induced phytoplankton blooms impose nutrient stress on coral reefs.
• Regional nutrient management is crucial for reef survival under the pressure of climate change.

Anthropogenic nutrient enrichment is often associated with coral reef decline. Consequently, there is a large consent that increased nutrient influxes in reef waters have negative longterm consequences for corals. However, the mechanisms by which dissolved inorganic nutrients can disturb corals and their symbiotic algae are subject to controversial debate. Herein, we discuss recent studies that demonstrate how nutrient enrichment affects the heat and light stress tolerance of corals and their bleaching susceptibility. We integrate direct and indirect effects of nutrient enrichment on corals in a model that explains why healthy coral reefs can exist over a rather broad range of natural nutrient environments at the lower end of the concentration scale and that anthropogenic nutrient enrichment can disturb the finely balanced processes via multiple pathways. We conceptualise that corals can suffer from secondary negative nutrient effects due to the alteration of their natural nutrient environment by increased phytoplankton loads. In this context, we suggest that phytoplankton represents a likely vector that can translate nutrients effects, induced for instance by coastal run-off, into nutrient stress on coral reefs in considerable distance to the site of primary nutrient enrichment. The presented synthesis of the literature suggests that the effects of nutrient enrichment and eutrophication beyond certain thresholds are negative for the physiological performance of the coral individual and for ecosystem functioning. Hence, the immediate implementation of knowledge-based nutrient management strategies is crucial for coral reef survival.

Special thanks to Coral-list @ noaa.gov

Ecotoxicology: Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, *Stylophora pistillata* by C. A. Downs • Esti Kramarsky-Winter • John E. Fauth • Roee Segal •Omri Bronstein • Rina Jeger • Yona Lichtenfeld • Cheryl M. Woodley • Paul Pennington • Ariel Kushmaro • Yossi Loya

The article is in the journal Ecotoxicology. A link to the article can be
found at http://link.springer.com/article/10.1007/s10646-013-1161-y

Accepted: 7 December 2013

Abstract Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an ‘‘emerging contaminant of concern’’ that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic
fields and unmanaged cesspits. AlthoughBP-2may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light,
BP-2 induced coral planulae to transformfromamotile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the
light induced extensive necrosis in both the epidermis and gastrodermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death. The LC50 of BP-2 in the light for an 8 and 24 h exposure was 120 and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 and 548 ppb. Deformity EC20 levels (24
h) were 246 parts per trillion in the light and 9.6 ppb in darkness.

Marine Pollution Bulletin 44 (2002) 1206–1218: Characterizing stress gene expression in reef-building corals exposed to the mosquitoside dibrom q

Morgan and Snell 2002 Dibrom

Michael B. Morgan *, Terry W. Snell
Georgia Institute of Technology, School of Biology, Atlanta, GA 30332-0230, USA

We characterize two genes expressed in Acropora cervicornis upon exposure to 0.5 lg/l of dibrom, a pesticide used for mosquito control in the Florida Keys. Fragments of these genes were isolated, sequenced, and developed into chemiluminescent probes for Northern slot blots. Expression of target transcripts was detected in corals exposed to a variety of stressors including organophosphates, organochlorines, heavy metals, naphthalene, and temperature. Within the context of stressors examined, the D25 probe demonstrates toxicant and concentration specificity for organophosphates, whereas the D50 probe had broader specificity, detecting transcripts in corals exposed to dibrom, naphthalene, and temperature stress. After characterizing specificity in the lab, these probes were used on field samples taken from the Florida Keys. Both probes detected their targets in samples taken from the upper Florida Keys in August 2000. Preliminary search of sequence databases suggest similarity exists between D25 and a thioesterase.

MARINE ECOLOGY PROGRESS SERIES: Insecticides and a fungicide affect multiple coral life stages


Mar Ecol Prog Ser
Vol. 330: 127–137, 2007 Published January 25

Kathryn L. Markey1, 2, Andrew H. Baird3, Craig Humphrey2, Andrew P. Negri2,*
1 School of Marine Biology and Aquaculture, and 3ARC Centre of Excellence for Reef Studies, James Cook University,
Townsville, Queensland 4811, Australia
2 Australian Institute of Marine Science, PMB
3, Townsville, Queensland 4810, Australia

ABSTRACT: Coral reefs are under threat from land-based agricultural pollutants on a global scale.
The vulnerability of early life stages of corals is of particular concern. Here, we compared the sensitivity
of gametes, larvae and adult branches of the broadcast-spawning coral Acropora millepora
(Ehrenberg) to a number of common pollutants, including 4 classes of insecticides—2 organophosphates
(chlorpyrifos, profenofos), an organochlorine (endosulfan), a carbamate (carbaryl) and a
pyrethroid (permethrin)—and a fungicide (2-methoxyethylmercuric chloride, MEMC). Fertilisation
of gametes was not affected by any of the insecticides at concentrations up to 30 μg l–1. In contrast,
settlement and metamorphosis were reduced by between 50 and 100% following 18 h exposure to
very low concentrations (0.3 to 1.0 μg l–1) of each insecticide class. The insecticides had few visible
effects on adult branches following 96 h exposure to a concentration of 10 μg l–1, with the exception
of profenofos, which caused polyp retraction, bleaching (i.e. algal symbiont densities were reduced)
and a slight reduction in photosynthetic efficiency of the algal symbionts. The fungicide MEMC
affected all life-history stages: both fertilisation and metamorphosis were inhibited at 1.0 μg l–1, and
polyps became withdrawn and photosynthetic efficiency was slightly reduced at 1.0 μg l–1. At 10 μg
l–1 MEMC, branches bleached and some host tissue died. This high susceptibility of coral larvae to
pesticides at concentrations around their detection limit highlights the critical need to assess toxicity
against all life-history stages of keystone organisms: to focus on mature individuals may underestimate
species sensitivity.