Abstract:
Climate change is posing unprecedented pressure onto marine ecosystems worldwide.
This makes it imperative to monitor the effects that are being experienced in
these environments. Nudibranchs are benthic marine organisms that possess characteristics
that have the potential to act as indicators of change within ecosystems such
as coral reefs. Therefore, these species have the ability to provide valuable information
on fine-scale changes in environmental conditions. It is thus essential for studies,
such as this, to establish baseline analyses from which changes within nudibranch
populations can be examined in order to investigate their ability to act as bioindicators.
Recommendations can also be made for future sampling procedures through
investigating environmental and experimental parameters that influence nudibranch
communities. Nudibranch populations were sampled on Two-Mile Reef in Sodwana
Bay, South Africa, through SCUBA where individuals were photographed and later
identified. Data were collected within a sample-based dataset, as well as by citizen
scientists within an incidence-based dataset. Across both datasets, a total of 85 species
were identified. Nudibranch populations showed high levels of diversity within an
uneven, unstable community. Citizen scientist data provided imperative information
to the baseline assessment and, therefore, the inclusion of these data increased the
robustness of this study. Environmental and experimental variables investigated did
not influence the outcomes of this study and should therefore not be heavily focused
on in designing future experiments. Future monitoring studies should continue to record
oceanic pH in order to detect any possible changes due to ocean acidification.
It is recommended that sampling events should be increased in order to capture all
species present in these localities. These events should also encompass an extended
temporal scale in order to cover a larger temperature range. Research on bioindicators
is essential within today's rapidly changing climate, mainly due to human activities,
particularly within an extremely vulnerable habitats such as coral reefs.
