Preliminary Monitoring of Whale Shark (Rhincodon typus) Migration Patterns in the Waters Botubarani Village Gorontalo Based on Satellite Marker Monitoring

This research aims to determine the migration patterns of Whale Sharks using satellite markers in the waters of Botubarani Village, Bone Bolango Regency, Gorontalo Province. This research was conducted from April 2023 to December 2023 using satellite-based technology by installing satellite tagging (Finmount Tag) on two individual whale sharks that often appear at the research location with codes ID 53 and ID 55. Tagging was carried out using the containment method. using nets and boats. The results showed that the two individuals showed different migration patterns both spatially and temporally. The individual with ID code 53 was recorded as having migrated for 79 days and the individual with ID code 55 was recorded as having migrated for 54 days to return to Botubarani beach, Gorontalo. Based on monitoring results, the two of them have different migration patterns but are still in the Tomini Bay waters. The results of this research have contributed to knowledge about the behavior of Whale Sharks (Rhincodon typus) in the waters of Tomini Bay which can be useful as a basis for future management.


INTRODUCTION
The waters of Botubarani Village, Kabila Bone District, Bone Bolango Regency, which is part of the Tomini Bay area, are the location where Whale Sharks appear in Indonesia.Based on information from local fishermen, the appearance of whale sharks in Botubarani waters and its surroundings has actually been around for a long time, but the exact time is not known.This can be proven by the mention of this fish with the local name Munggiangohulalo.
This fish usually only appears at certain times.They sometimes appear every day but sometimes they don't appear and then disappear from Botubarani waters.According to local fishermen, these fish are usually a nuisance during the nike fish emergence season because they usually swim near boats and prey on the nike fish that are the target of catching them.
Nike fish are small fish that appear in the waters of Gorontalo Bay at the end of the month to the beginning of the month in the Hijri calendar year (Olii, et al. 2017;Bahani, et al. 2019).Based on information from local fishermen and from observations, this fish will usually move to locations where there is nike fishing.It is suspected that the presence of Whale Sharks in Botubarani waters and its surroundings is related to food (Jonahson and Harding, 2007; Rahman, et al. 2017).The results of recent research on the sustainability of nike fish in the waters of Tomini Bay show that of the 5 dimensions analyzed there are 4 dimensions that are unsustainable (Sahami, et al. 2024).This will certainly be a threat to the continued emergence of Whale Sharks in Botubarani.
The existence of Whale Sharks in the waters of Botubarani Gorontalo has become known to the wider public since 2016 and with the power of social media, now Botubarani has become one of the Whale Shark tourist attractions in Indonesia which is well known and has even reached foreign countries.This of course must receive serious attention for good management so that its existence is sustainable.
Several researches related to this fish in Botubarani have been carried out, including by Rahman, et al.Information about whale shark migration patterns is very important considering that Gorontalo is one of the regions in Indonesia which is a priority for marine biodiversity conservation, especially whale sharks.Rahman, et al. (2017) stated that the appearance of whale sharks in the waters of Tomini Bay cannot currently be predicted accurately.Documenting the movement and behavior of marine animals poses great challenges due to their high mobility and the influence of diverse water conditions (Martin, et al., 2009).With current advances in technology, tracking using satellite tags can enable scientists to understand the movement and roaming patterns of animals with satellite tags attached (Bailey, et al. 2010).Therefore, the research has used satellite markers to determine the migration patterns of Whale Sharks that appear in Botubarani waters over a long and continuous period of time to obtain accurate data and information.It is hoped that the results of this research can contribute to the development of knowledge about Whale Sharks, especially in Botubarani and

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Indonesia as well as in all countries that are migration areas for this fish, so that comprehensive management can be carried out.

RESEARCH METHODOLOGY
This research was carried out during the period April to December 2023.To determine the migration pattern of the Botubarani Gorontalo Whale Shark, a satellite tag method was used which was attached to the Whale Shark to be observed.Migration pattern observations were carried out on two individual whale sharks which were identified with codes ID 53 and ID 55.
The satellite marker used in this research is the SPLASH10-346A type made by Wildlife Computers with dimensions of 198 mm x 84 mm x 23 mm.This tool has been specially designed for mounting on the dorsal fin of a Whale Shark with a large battery pack.This marker has the ability to work up to 450 days if it does not experience physical damage.
The tag installation uses a confinement method using a fine net (resembling a mosquito net) measuring 20 x 50 meters so as not to injure the Whale Shark specimen.In this installation, 3 boat aids and scuba diving equipment and an underwater camera were used.
Retrieval of data from satellite signal receivers via the wildlife computer portal on Whale Sharks ID 53 and ID 55 which have satellite tags installed.Through this wildlife computer portal tool, the condition of the parameters of temperature, depth and migration coordinates of Whale Sharks can also be known.The Whale Shark migration data studied both spatially and temporally were analyzed descriptively.

I. RESULTS
The results of observations of the spatial temporal distribution patterns of 2 (two) individual Whale Sharks with ID GT 53 and ID GT 55 which had satellite tagging installed showed different patterns.After embedding the satellite tagging device, the two individuals gave their first signal to the satellite which was successfully read by the wildlife computer application software at different time intervals.The research results provide interesting results.These two individuals show different spatial migration patterns horizontally and vertically.Likewise, the temporal migration pattern shows that the two spend different times completing their migration process to return to Botubarani waters after migrating in the Tomini Bay area.

Whale Shark Horizontal Migration Patterns
The results of the analysis of the horizontal spatial distribution patterns of the two observed individuals are presented in Figure 1.47 the maximum depth recorded was 480 meters (Figure 2).The presence of the ID 53 Whale Shark at its maximum depth was observed twice, namely on February 5 2023 and March 20 2023.From Figure 2, the vertical movement of the ID 53 Whale Shark is often at a depth of 375 meters with a frequency recorded 10 times at that depth. .The graphic data on the vertical movement of whale shark ID 53 shows that their activity is mostly on the surface, which is thought to be due to their search for food on the surface of the waters.Figure 2 also shows that the vertical migration pattern of individual ID 53 tends to have the same pattern between minimum depth and maximum depth.
The vertical movement of the Gorontalo Botubarani Whale Shark ID 55 is almost the same as individual ID 53, where it is more dominant at the surface of the water, namely 030 meters, which is also thought to be looking for food.The deepest depth recorded based on satellite tagging results is 528 meters, but the ID 55 whale shark is often also at a depth of 175 meters, which was recorded 10 times in its vertical movement phase during the 5 months since the satellite tagging device was installed.The vertical migration pattern at minimum and maximum depth of individual ID 55 is presented in Figure 3. Figure 3 shows that the vertical migration pattern of individual ID 55 is different from ID 53.This vertical migration pattern may be caused by foraging activities towards the water surface and the availability of food at the migration location.The behavior of stopping for a moment before continuing spatial migration activities cannot be known with certainty.
The results of recording temperature data using data from the ID 53 satellite tagging show that the ID 53 Whale Shark individual has an activity niche at a temperature of 29oC to 30oC, which is the ideal temperature for the whale shark's habitat environment.The lowest temperature fluctuation based on data is 27.5oC and the highest is 31oC.Temporary The results of recording temperature data on ID 55 show that the water temperature conditions for the ID 55 aggregation were recorded as the highest being 32.7oC and the lowest being 27.9oC.The temperature detected is the temperature of the environment according to the movement where the whale shark is, both vertical movement and horizontal movement of the whale shark.

DISCUSSION
The horizontal movement of whale sharks during migration is their attempt to find food (Handoko, 2017).The movement of whale sharks is also influenced by many factors, one of which is the availability of food at a whale shark aggregation location which has been proven through the results of research on seven individual whale sharks who were tagged and released from the Ningallo Reef area into the Indian Ocean, the results of which have shown that the movement of whale sharks following the movement of plankton as animal food carried by surface currents in the Indian Ocean (Sleeman, et al. 2010).Whale sharks have a pelagic habitat, which means that whale sharks prefer to spend time on the surface of the waters, but are often found in open waters to coastal waters, sometimes even entering lagoon areas (Rahman, et al. 2017).
According to Rosalina et al. (2021) that the wandering nature of Whale Sharks while feeding by filtering has caused Whale Sharks to move in and out of Botubarani waters.When there are no tourists or management providing shrimp waste or small fish, the Whale Sharks will move to other places to look for more food.The phenomenon that can be seen is during the nike fish season.Maruanaya, et al. (2022) reported that the number of individuals appearing in Kwatisore waters is closely related to the catch of anchovies by Bagan fishermen.
Migration to the surface is often carried out in order to find food in the form of plankton and small fish as well as crustaceans and squid.According to Rosalina, et al. (2021) that Whale Sharks in Botubarani waters tend to spend their time in shallow waters at a depth of less than 50 meters or close to the surface because (2017) who conducted an initial study on the emergence of whale sharks in Tomini Bay which was linked to physical and biological factors in the water.Then Rombe, et al. (2022) who conducted a study on the condition of the whale shark population and measured several water quality parameters.Meanwhile, information about the distribution pattern of Whale Sharks that appear in Botubarani waters is not yet available.Whale sharks can influence community structure and function through top-down density effects and risk-based effects on the distribution and abundance of their prey (Heithaus, et al. 2008).Predicting migration and aggregation patterns as well as anthropogenic impacts is very important (Hammerschlag, et al. 2010).
/© 2024 The Authors.Published by Academic Journal INC.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/)

Figure 1 .
Figure 1.Spatial distribution pattern of Whale Sharks in the waters of Tomini Bay.A).Individual with ID 53; B).Individual with ID 55.

Figure 2 .Figure 3 .
Figure 2. Vertical Movement Graph of Whale Shark ID 53 during the research