Use of local ecological knowledge in the management of algal blooms

Abstract

More frequent and severe algal blooms are symptomatic of increasing ecosystem stress in coastal waters. Economic losses typically follow and local governments are forced to 'manage' this issue. Because many blooms are not monitored, local ecological knowledge (LEK) and oral history are the only practical tools to obtain data on bloom characteristics and identify their drivers. LEK was applied to outbreaks of brown algae on popular tourist beaches in south-east Queensland (Australia). Structured interviews with local citizens who had a close and frequent connection with the ocean provided 541 bloom records, which showed that blooms are regional (≥400 km) rather than local, and that they are a historical (≥40 years) rather than a recent phenomenon. LEK frequently cited that particular wind regimes coincided with the arrival of blooms, but this could not be verified by statistical cross-validation with empirical data. Harnessing LEK was valuable in engaging citizens, in generating testable hypotheses about plume causes, in providing a previously unrecognized historical perspective and in identifying the correct spatial scale of the issue. Multi-pronged approaches will be most effective in addressing blooms where local mitigation actions are combined with broader regional coastal environmental conservation efforts.

Baseline survey of the fish and invertebrate fauna of Hill Inlet, the northernmost estuary in south-western Australia

“…As the data 327 in this study were collected over a small temporal window sampling should be repeated at a 328 time of the year when water levels are lower, either during summer or again in winter, but only 329 after the bar has broken to provide a more holistic assessment of the fauna of Hill Inlet. In the 330 meantime, given the lack of scientific information available on Hill Inlet, there would be value 331 in engaging with the community, such local ecological knowledge has been shown to be useful 332 in informing decision making and management (Schlacher et al, 2010;Obregón et al, 2020).…”

The value of oral history in natural resource management: the Balcombe Estuary Reserve, Mount Martha, Victoria

“…This can be particularly valuable in areas where there is limited existing information on changing ecologies (Schlacher et al 2010). …”

“…As outlined by Schlacher et al (2010), local ecological knowledge (in our study elicited through interviews) can be valuable for generating testable hypotheses for future research. Our case study has identified a number of further research areas, including the impact of urbanisation pressure and the perceived extent of species decline.…”

“…Our case study has identified a number of further research areas, including the impact of urbanisation pressure and the perceived extent of species decline. Oral history investigations can highlight aspects of change that may have otherwise been overlooked when planning conventional scientific research (Schlacher et al 2010). For example, responses relating to the island in the estuary give an insight into the extent of sedimentation that may have otherwise gone undetected.…”

“…Use of oral history in ecosystem management can be highly effective when devising specific management objectives for holistic planning and conservation of a highly pressured system (Robertson et al 2000;Schlacher et al 2010). However, it has been widely criticised (see Tibby et al 2008) and has emerged only recently as a credible environmental indicator (Robertson et al 2000;Robertson & McGee 2003).…”