Muawanah. 2012. Pasang Merah Muncul di Teluk Lampung. Koran Lampung Post. 25
Oktober 2012
Risuana, IGS., IG Hendrawan, dan Y Suteja. 2017. Distribusi Spasial Total Padatan
Tersuspensi Puncak Musim Hujan Di Permukaan Perairan Teluk Benoa, Bali. Journal of
Marine and Aquatic Sciences 3(2), 223-232.
Suteja, Y.., AIS Purwiyanto. 2018. Nitrate and phosphate from rivers as mitigation of
eutrophication in Benoa bay, Bali-Indonesia. IOP Conf. Series: Earth and Environmental
Science 162 , 012021
Suteja, Y., IGNP Dirgayusa. 2017. Deteksi Awal Eutrofikasi Teluk Benoa Sebagai Upaya
Mitigasi Harmful Alga Blooms (HABs). Laporan Akhir HUPS.
Wardiatno Y., A. Damar dan B. Sumartono. 2004. A Short Review on the Recent Problem
of Red Tide in Jakarta Bay: Effect of Red Tide on Fish and Human. Jurnal Ilmu-Ilmu
Perairan dan Perikanan Indonesia. Vol 11(1):67-71
Introduction Eutrophication defined as an increase the amount of organic material (especially plankton and or
chlorophyll) in an aquatic ecosystem caused by the increasing of nutrients by human activities.
The most dangerous eutrophication effect is Harmful Alga Blooms (HABs). HABs are an increase
in the abundance of individual plankton in aquatic ecosystems which can cause anoxia or
hypoxia or the production of poisons that can cause the death for organisms . HABs started by
eutrophic condition have occurred in Lampung and Jakarta Bay (Wardianto et al., 2004
Muawanah, 2012). Previous research showed that Benoa Bay in hypereutrophic base on
nutrient. This can initiate the growth of chlorophyll and phytoplankton for HABs. This study aims
to identify the types and abundance of potentially HABs phytoplankton, and determine the trophic
level based on chlorophyll and phytoplankton in Benoa Bay
CHLOROPHYLL AND PHYTOPLANKTON ANALYSIS FOR INITIAL DETECTION
OF EUTROFICATION AND HARMFUL ALGA BLOOMS (HABs) IN BENOA BAY Y. Suteja1*, I G. N. P. Dirgayusa1
1Marine Science Department, Faculty of Marine and Fisheries, Udayana University. Jalan Raya Kampus Kampus Bukit Jimbaran, Universitas Udayana
*Corresponding author: [email protected]
Research Methods
Results and Discussion Conclusion This study found that there were 6 genera that had the potential of HABs. The
abundance of phytoplankton and chlorophyll shows an increase concentration near the
land and river estuary. The Coscinodiscus is a genus with the highest abundance.
Trophic level in Benoa Bay based on phytoplankton abundance and chlorophyll
concentration are oligotrophic. Even though Benoa Bay dominated in oligotrophic
category, the alertness of HABs must be considered because there is 1 genus that has
the potential to produce toxins and 5 genuses that can cause damage if algae blooms
occur.
Thank You Note The author give thanks to Udayana University for fully supporting this research through
Hibah Unggulan Program Studi. We also thanks to Anna Ida for her friendly constructive
suggestion and discussion.
Bibliography
Data Collection
INSITU (pH, Temperature, Salinity, DO, Turbidity)
EXSITU (Chlorophyll and phytoplankton abundance)
Spatial Mapping
Trophic Level
Figure 2. Abundance of HABs (red) and non-HABs (Green) plankton in Benoa Bay
Figure 1. research methods
Figure 3. Percentage of HABs (red) and
non-HABs (Green) plankton abundance in
Benoa Bay
From the identified phytoplankton, there were 6
genera that were potentially HABs. From the 6
genera, only one genera can be found which
can produce toxins (Nitzicia), while the other
genera (Coscinodiscus, Skeletonema,
Chaetoceros, Odontella, and Rhizosolenia) are
genera that cannot produce toxins but can
cause damaging effects if the population
blooming.
This study also show that the Benoa Bay was
dominated (75%) by plankton that have
potential of HABs (Figure 3).
Figure 4. Spatial distribution of plankton (left) and chlorophyll (right) in Benoa Bay
Figure 5. Trophic Level of plankton (left) and chlorophyll (right) in Benoa Bay
This study show that the plankton abundance and chlorophyll concentration increase
near the land and estuary (Figure 4). This is allegedly caused by an increase in nutrients.
Previous research by Suteja and Dirgayusa (2017) and Rahayu et al. (2018) shows an
increase of nutrient concentrations near land and estuary. Suteja and Purwiyanto (2018)
also explained that the nutrient load from the river to the Benoa Bay was very large.
Based on plankton abundance and chlorophyll concentration, Benoa Bay is in
oligotrophic condition (Figure 5). This is presumably due to the high turbidity and Total
Suspended Solid (TSS) which reducing the sunlight penetration. Risuana et al (2017)
explained that TSS concentrations in Benoa Bay had exceeded the quality standards set
by the government.