Fungal Growth in Polluted New Zealand Mangrove Sediments and an Examination of Sediment Fungal/Bacterial Isolates from Auckland’s Waitemata Harbor

Microorganisms are pivotal in mangrove ecosystems, serving as recyclers and transformers of nutrients in these typically nutrient-limited areas. Auckland’s Waitemata Harbor houses several mangrove stands that are polluted with a slew of hydrocarbons and heavy metals. The primary objective of this study is to identify the level of PAH/heavy metals from Waitemata Harbor mangrove stands that may impact fungal growth. Secondarily, this experiment sought to characterize the microorganisms naturally present within the sediments. Two sites were selected from around the Harbor: Hobson Bay (highly polluted) and Herald Island (less polluted), the sediments from which were either autoclaved or non-autoclaved, inoculated with a growth medium (MEA) along a dilution gradient, inoculated with three species of fungi, and incubated on petri dishes for approximately 20 days. Plates with autoclaved sediment were used to determine the sediment to agar ratio that would allow the most successful fungal growth over time. Plates with non-autoclaved sediment were used to culture the microorganisms naturally present in the sediments. Results indicated that Hobson Bay sediments in higher concentrations are detrimental to Ileodictyon cibarium growth. Trichoderma, Bacillus, Talaromyces and Penicillium species grew on plates with non-autoclaved Hobson Bay sediment, while only Talaromyces species grew on Herald Island sediments. This experiment provides insight into the fungal community composition of the two sites, and may serve as an introductory examination of the bioremediation potential of fungi within the Harbor ecosystem