Publications by authors named "Mark Hearnden"

We evaluated spatial and temporal variability in parasite communities from the commercially important tropical marine fish the black-spotted croaker (Protonibea diacanthus) (Teleostei: Sciaenidae) to examine its population structure off the coast of the Northern Territory, Australia. Differences in parasite assemblage between four locations, across three seasons of the year, were used to evaluate the degree of connectivity of the sciaenid across coastal study areas. Analysis of parasite prevalence and mean intensity in these fish suggested the four sampling sites are distinct host populations.

View Article and Find Full Text PDF

f.sp. , causal agent of Panama disease, is one of the biggest threats to global banana production, particularly the Cavendish competent tropical race 4 ( TR4).

View Article and Find Full Text PDF

As pressure on coastal marine resources is increasing globally, the need to quantitatively assess vulnerable fish stocks is crucial in order to avoid the ecological consequences of stock depletions. Species of Sciaenidae (croakers, drums) are important components of tropical and temperate fisheries and are especially vulnerable to exploitation. The black-spotted croaker, , is the only large sciaenid in coastal waters of northern Australia where it is targeted by commercial, recreational and indigenous fishers due to its food value and predictable aggregating behaviour.

View Article and Find Full Text PDF

Understanding the root distribution of trees by soil coring is time -: consuming as it requires the separation of roots from soil and classification of roots into particular size classes. This labour-intensive process can limit sample throughput and therefore sampling intensity. We investigated the use of quantitative polymerase chain reaction (qPCR) on soil DNA extractions to determine live fine root DNA density (RDD, mg DNA m(-2)) for mango (Mangifera indica) trees.

View Article and Find Full Text PDF

New Zealand has one of the highest incidences of campylobacteriosis in the developed world, which leads a global trend of increasing notifications of Campylobacter infections over the last decade. Foodborne and waterborne transmission have been implicated as significant mechanisms in the complex ecology of the disease in New Zealand. We examined both regional and temporal variation in notification rates to gain some insight into the role of the New Zealand environments in modifying disease incidence.

View Article and Find Full Text PDF

This study illustrates the impact of address geocoding uncertainty on rural estimates of reportable disease incidence using campylobacteriosis as an example. After all cases of campylobacteriosis notified from 1993 to 1997 had been geocoded, the minimum and maximum disease notification rates were calculated for rural and urban areas of New Zealand. The estimated maximum rural rates were four times higher than estimated minimum rural rates, whereas estimated minimum and maximum urban rates varied minimally.

View Article and Find Full Text PDF