The Abundance of Potentially Toxic Epiphytic Dinoflagellates and Nutrients From Bali and Gili Trawangan, Indonesia

Abstract

There are strong indicators that the degradation of coral reefs may increase the intensity and frequency of ciguatera fish poisoning (CFP) outbreaks when denuded reef surfaces are colonised by macro algae that are the preferred hosts of toxic dinoflagellates that can cause the disease. Ciguatera field studies have concentrated on the dinoflagellate genus Gambierdiscus, well known to be the producer of ciguatoxin precursors. Moreover the potential of toxins from other dinoflagellate genera such as Prorocentrum and Ostreopsis is less often considered. Whilstit is known that toxic compounds produced by Ostreopsis species include ostreotoxins (OTX) and ostreocins, the potential harmful impacts of Ostreopsis, Prorocentrum and Gambierdiscus species on coral reef organisms (and ecological impacts) are largely unknown. In addition, CFP has historically largely occurred on the oceanic islands of the world’s tropical seas, but has only recently been reported in the major archipelagoes of Indonesia and thePhilippines. In view of their degraded coral reef ecosystems and the potential link between reef health and CFP, this study examined three sites in Bali and Gili Trawangan over one year, to assess the prevalence and distribution of CFP related dinoflagellate species. Beside finding Gambierdiscus, Ostreopsis and Prorocentrum at most sites, water column nitrogen nutrient levels were also found on the average to be 3−4 times higher than that recommended for a healthy coral reef (0.013mg/L). However the maximum abundance of Prorocentrum, Ostreopsis and Gambierdiscus found were low (103, 2,860 and 28 cells per gram of wet weight of host macroalgae, respectively). A factor thatmay play a part in the potential for toxicity at these sites is the abundance of sea grass (and associated micro flora and fauna) which are often present within and adjacent to coral reef ecosystems across the Indonesian archipelago.

Ecology of the ciguatera causing dinoflagellates from the Northern Great Barrier Reef: Changes in community distribution and coastal eutrophication

“…Four of those sites showed a direct correlation with the Prorocentrum abundance and the water column DIN. A similar study of a smaller lagoon in Nusa Dua, Bali, Indonesia also found a significant correlation between the dinoflagellate genera Prorocentrum with the DIN in the water column (Skinner et al, 2012), and a benthic Prorocentrum gillespii bloom in the sediment of Muri lagoon, Rarotonga was also correlated with nutrients (Skinner et al, 2009), where critical levels for nutrient thresholds were also exceeded at both sites. The genus Prorocentrum is known to be involved in ciguatera (Rongo and Van Woesik, 2010), so nutrient thresholds set for coral reefs should be employed, as these levels once exceeded, can assist to create HABs.…”

Detection of marine microalgae (phytoplankton) quality to support seafood health: A case study on the west coast of South Sulawesi, Indonesia

“…Some of the acute diseases caused by toxins from microalgae in the HABs group are paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), diarrhetic shellfish poisoning (DSP) (Fukuyo et al 2011;Krock et al 2018), and ciguatera fish poisoning (CFP) (Skinner et al 2011). These toxins are hazardous to human health because they attack the nervous system and interfere with respiration and digestion.…”

“…These diseases are related to the human consumption of fish and shellfish. Many types of toxic phytoplankton can be found in Indonesian coastal waters, including several Dinoflagellate species from the genera Noctiluca, Gymnodinium, Cochlodinium, Ceratium, Peridinium, Gonyaulax, Ostreopsis, Prorocentrum, and Gambierdiscus (Adnan 1984;Adnan 1989;Skinner et al 2011;Hasani et al 2013;Aditya et al 2015). One HAB event in 1993 took place in Jakarta Bay, where a mass fishkill was caused by the excessive abundance of phytoplankton that can cause HABs.…”

Morphotype diversity of Prorocentrum lima in the western part of Indonesian waters

“…Prorocentrum has been reported in Indonesian waters. For instance, in Seribu Islands (Penjaliran Barat Island, Pramuka Island, Panggang Island, Semak Daun Island, Pari Island, Air Island and Tidung Island) (Widiarti 2002;Widiarti 2011;, Belitung Island (Buyut Island, Kelayang Cape, and Keran Island) (Widiarti 2010), Bali waters (Kuta, Sanur, and Nusa Dua), Lombok (Gili Trawangan) (Skinner et al 2011), west coast of South Sumatera and Bintan Island coast-Riau Islands (Thamrin 2014), Padang city beach waters (Dwivayana 2015;Eboni et al 2015;Oktavian et al 2017;Seygita et al 2015), North Lombok (Gili Meno and Gili Air) (Widiarti et al 2016a), South Lampung waters (Pahawang Besar Island and Kelagian Kecil Island) (Widiarti and Adi 2016), and Weh Island waters-North Aceh (Rubiah Island) (Widiarti et al 2016b). However, no detailed observation on cell surface morphology has been recorded.…”