James Tucker

Southern Cross University · National Marine Science Centre (NMSC)

The co-occurrence of people and sharks within nearshore areas raises concerns about human safety. Unprovoked shark bites are one of the most renowned negative human–wildlife encounters. White sharks (Carcharodon carcharias) are implicated in most fatal unprovoked shark bites globally, but there is limited knowledge of white shark behaviour in the p...

The wave-impacted waters off exposed sandy beaches support marine megafauna, including dolphins, whales, sharks, rays and turtles. To characterise variation in megafaunal assemblages in this challenging habitat, we used drone-based remote sensing to survey marine megafauna off 23 beaches along 1050 km of the New South Wales (NSW, Australia) coast f...

The perceived and real threat of shark bites have significant direct health and indirect economic impacts. Here we assess the changing odds of surviving an unprovoked shark bite using 200 years of Australian records. Bite survivability rates for bull (Carcharhinus leucas), tiger (Galeocerdo cuvier) and white (Carcharodon carcharias) sharks were ass...

Nitrogen loss via overland flow from agricultural land use is a global threat to waterways. On-farm denitrifying woodchip bioreactors can mitigate NO3⁻ exports by increasing denitrification capacity. However, denitrification in sub-optimal conditions releases the greenhouse gas nitrous oxide (N2O), swapping the pollution from aquatic to atmospheric...

Flood events can transport large nitrogen loads to the ocean in short periods with the potential to produce significant nitrous oxide (N2O) emissions along an estuarine gradient. Here, we evaluate temporal and spatial N2O air-water fluxes from both seasonal, and flood-event timescales in an urban subtropical estuary surrounded by mangroves (Coffs C...

Long-term coral reef resilience to multiple stressors depends on their ability to maintain positive calcification rates. Estimates of coral ecosystem calcification and organic productivity provide insight into the environmental drivers and temporal changes in reef condition. Here, we analyse global spatiotemporal trends and drivers of coral reef ca...

The disposal of whale carcasses in beach burials has raised perceptions of shark attraction to the adjacent water. Understanding the concerns and perceptions of the community is key to creating sound management practices and educational resources. We surveyed community perception of the disposal of whale carcasses and the factors influencing public...

Coastal waterways can be significant sources of the potent greenhouse gas nitrous oxide (N 2 O) due to nitrogen inputs and eutrophication. Here, we quantify groundwater derived N 2 O inputs and atmospheric emissions within a modified urban embayment (Sydney Harbour, Australia). Overall, we found low N 2 O saturation (91-171%) and air-water fluxes (...

White sharks (Carcharodon carcharias) are attracted to and scavenge on floating whale carcasses. However, little is known about how stranded whale carcasses may affect their behaviour. With increasing whale populations and beach stranding events, sharks may be attracted to nearshore waters at carcass sites, increasing the potential conflict with hu...

Nitrogen pollution in subtropical waters is rapidly increasing due to land-use change, but specific sources, transformations, and attenuation rates remain understudied compared to cooler temperate catchments. Here, we quantify high-resolution nitrate (NO3⁻-N) loads, sources and natural attenuation in a subtropical creek in Australia over contrastin...

Over the past decade, drones have become a popular tool for wildlife management and research. Drones have shown significant value for animals that were often difficult or dangerous to study using traditional survey methods. In the past five years drone technology has become commonplace for shark research with their use above, and more recently, bel...

Submarine groundwater discharge (SGD) is rarely considered as a pathway for contaminants of emerging concern (CECs). Here, we investigated SGD as a source of CECs in Sydney Harbour, Australia. CEC detection frequencies based on presence/absence of a specific compound were >90% for caffeine, carbamazepine, and dioxins, and overall ranged from 25 to...

We report water quality observations along a transect of Double Crossing Creek, a tributary of Hearnes Lake which drains to the Solitary Islands Marine Park. We quantify nitrogen (N) loads and the capacity of the creek to attenuate N runoff naturally. We also use stable isotopes to assess the contribution of N derived from recycled greywater versus...

The effects of urbanization and scales on submarine groundwater discharge (SGD) remain poorly understood. Here, we used radium isotopes to quantify SGD-derived fluxes of N, P and C into Sydney Harbour estuary, Australia. Sydney is the most populated city of Oceania, with several localised cases of historical groundwater pollution. We sampled top an...

Intertidal wetlands can sequester pollutants along estuarine conduits. Here we test the effectiveness of a mangrove-dominated estuary in removing dissolved nitrogen during a rain event. We intensively and simultaneously sampled surface water nutrients upstream and downstream of an estuary before, during and after a 63 mm rain event in Coffs Creek (...

Sharks are well known to scavenge whale carcasses, but observations are rare. Here we (1) describe new observations of whale carcass scavenging behaviour by white (Carcharodon carcharias) and tiger (Galeocerdo cuvier) sharks, and (2) review the scientific and grey literature on the topic. Our new observations are from the east coast of New South Wa...

Mangrove soil carbon stocks are known to decrease following forest loss due to respiration and enhanced soil CO2 emissions. However, changes in carbon outwelling to the coastal ocean due to mangrove forest disturbance have not been considered. In December 2015, an extremely large mangrove dieback event (~7000 hectares, spanning 1000 km of coastline...

With the recovery of whale populations, carcass strandings on beaches are growing. Beach burial is a common management option for stranded carcasses. However, communities fear shark attraction following leachate transport to the ocean via submarine groundwater discharge. Here, a sediment column mesocosm experiment indicated that carcasses can be a...

Submarine groundwater discharge (SGD) is an important link between the land and ocean. In this study, eddy diffusivity coefficients (Kh) and SGD rates were examined off the Jetty Beach in Coffs Harbour (Australia) in September 2017 and 2018. In order to estimate Kh, the apparent age and SGD, two short-lived radium isotopes ²²⁴Ra and ²²³Ra were meas...

The management of stranded whale carcasses is a logistical, environmental and economic challenge concerning a number of different stakeholders. In this paper, we review the current carcass disposal methods, stakeholders involved, and identify research needs and gaps. Examples of carcass disposals from all over the world are presented with Australia...

Coastal vegetation (seagrass, mangrove and saltmarsh) termed “blue carbon” systems have recently been noted for their potentially large carbon storage capacities. This study quantifies sedimentary blue carbon stocks in an urban estuary containing seagrass (Zostera muelleri), mangrove (Avicennia marina), and saltmarsh (Sporobolus virginicus) habitat...