Exposure of sunlight lead tropical Sargassum sp. to maintain their growth and moreover to bring up their secondary metabollite for life struggling. Sargassum sp. has bioactive compounds that has a potential antioxidant acitivity such as phenolic compounds as well as chlorophyll and carotenoids. This research was conducted to determine antioxidant activities, phenolic compound and pigmens of Sargassum sp. with different solvent that have different polarities. Sample was macerate with n-heksana, ethyl acetate, methanol and aquadest. All the parameters were done spectrophotometrically. IC50 was used to determine the antioxidant activity by antiradical scavenging activity using DPPH (515 nm). Total phenolic compound were tested by Folin-Ciocalteu solution  and used gallic acid as standard (725 nm). The chlorophylls a content were measured at wavelength 662 nm and 645 nm and carotenoids were measured at wavelength 470 nm. The results showed best IC50 is achieved by aquadest extract (72.95 ±0.22 ppm). The highest Total phenolic compound is achieved by ethyl acetat extract (120.29 ±0,404 mg GAE/g sample). The highest chlorophyll a content is achieved by ethyl acetat extract (18.23 ± 0,049 mg/g sample) and the highest carotenoid content is achieved by ethyl acetat extract extract (60.65 ±0,008  µmol/g sample). It can be concluded that aquadest extract can be categorized as the strong antioxidant and antiradical activity, ethyl acetat as a medium antioxidant activity. The simple and save methods of aquadest extract promising that Sargassum  sp. frorn Indonesia is a good candidate compoud for nutraceutical and cosmeceutical approach.

Antioksidan merupakan senyawa yang dapat menghambat atau mencegah reaksi oksidasi. Antioksidan sintetik kurang aman bagi kesehatan karena bersifat karsinogen, sehingga diperlukan sumber antioksidan alami seperti Padina sp. yang mengandung senyawa bioaktif seperti fenolat, klorofil a, karotenoid dan β-karoten. Padina sp. diambil dari Perairan Bandengan Jepara dan dikeringkan dengan Solar Tunnel Dryer (STD) selama 3 hari. Sampel dimaserasi secara bertingkat dengan pelarut n-heksana, etil asetat dan metanol lalu diuapkan dengan rotary evaporator. Aktivitas antioksidan ditentukan dengan metode DPPH (1,1-diphenyl-2-picrylhidrazyl) sebagai radikal bebas. Nilai IC50digunakan untuk mengetahui aktivitas antioksidan pada sampel yang diinkubasi selama 30 menit dan diukur nilai absorbansinya pada panjang gelombang 514 nm. Kandungan total fenolat diuji menggunakan larutan Folin-Ciocalteu dengan asam galat sebagai standar yang diukur pada panjang gelombang 725 nm. Kandungan klorofil a diukur pada panjang gelombang 663 nm dan 645 nm sedangkan karotenoid diukur pada panjang gelombang 480 nm. Hasil penelitian menunjukkan nilai IC50  terbaik dicapai ekstrak etil asetat yaitu 137,02 ppm, diikuti ekstrak n-heksana 1234,41 ppm dan ekstrak metanol 1554,45 ppm. Kandungan total fenolat tertinggi dicapai pada ekstrak etil asetat yaitu 12,09 mg GAE/g sampel, diikuti ekstrak n-heksana 9,32 mg GAE/g sampel dan ekstrak metanol 0,22 mg GAE/g sampel. Kandungan klorofil a tertinggi dicapai ekstrak etil asetat yaitu 2,67 mg/g sampel , diikuti ekstrak metanol 0,39 mg/g sampel dan ekstrak n-heksana 0,30 mg /g sampel. sampel). Kandungan karotenoid tertinggi dicapai ekstrak etil asetat yaitu 5,37 µ mol/g sampel, diikuti ekstrak n-heksana 1,85 µ mol/g sampel dan ekstrak metanol 0,53 µ mol/g sampel. Ekstrak etil asetat memiliki aktivitas antioksidan kategori sedang dan ekstrak metanol serta n-heksana memiliki aktivitas antioksidan kategori sangat lemah.

These study aimed to determine antioxidant activity, total phenolic compound and pigment content of tropical S. platensis, G. arcuata and U. lactuca. S. platensis was extracted with aquadest (SPA), while G. arcuata and U. lactuca were extracted with n-hexane (GAH and ULH), ethyl-acetate (GAE and ULE) and methanol (GAM and ULM). The IC50 value was used to calculate the ability of extract to inhibit free radicals using DPPH (515 nm). The TPC was determined using Folin-Ciocalteu (725 nm). Phycocyanin (620 nm), phycoerythrin (652 nm), allophycocyanin (562 nm), carotenoid (470 nm) and chlorophyll (645 nm and 662 nm) were measured based on color intensity. The results indicated that SPA was able to inhibit free radicals (46.12±2.03%), contains TPC (26.64±0.16 mg/GAE samples) and dominated by phycocyanin pigments (0.301±0.09 mg/g). G. arcuata extracted with ethyl-acetate (GAE) showed the best value with IC50 136.267±0.28 ppm, TPC 303.507±1.155 mg/GAE samples, carotenoid 0.528 ±0.009 μmol/g and chlorophyll a 2.845 ±0.069 mg/g. The U. lactuca extracted with ethyl-acetate also showed the best value with IC50 462.560±2.44 ppm, TPC 210.129±1.387 mg/GAE samples, carotenoid 0.442 ±0.046 μmol/g and chlorophyll a 9.216 ±0.103 mg/g. This results conlcuded that macroalgae extracted with ethyl acetate had better activity which categorized as moderate antioxidant.

The increasing use of plastic in various aspects of life impacts the increase in plastic waste in the environment. The plastics are degraded into the smallest fragments to a size of <5 mm called microplastics. Further, microplastics will accumulate in the water, marine biota, and sediment. Sea cucumbers are deposited feeder and found in the seagrass ecosystem. This study aims to examine the abundance of microplastics in sea cucumbers, which are scattered in seagrass ecosystems in the waters of Bintan Island and the surrounding area. The method used is a purposive random sampling in a seagrass ecosystem area of 100 × 20 meters. The sea cucumbers obtained will then be dissected and observed for their microplastic content. The results showed that the sea cucumber found in the seagrass ecosystem on the Bintan island are Holothuria atra, H. scabra, and Sticopus variegatus. The highest density of sea cucumbers was found in Pengujan waters, with a value of 90 ind/ha. The highest microplastic content in sea cucumbers was found in Pengudang water, with a total of 52 ± 7.68 particles/ind. The dominant type of microplastics is fiber, with a total of 84 particles/ind.

Alginate is rich in bioactive compounds and has been known to act as a stimulator on the innate immune system. The objective of this study is to determine polysaccharide and oligosaccharide alginate yield, that percentage inhibition with a different type of extraction, to evaluate growth performance as well as immune response by oxygen stress tolerance. Thermal heating with oven laboratory at 140oC for 4.5 hr was done to breakdown the polysaccharide into oligosaccharide. The extraction was conducted by maceration, filtration, precipitation, and centrifugation. Factorial design with two factors was implemented to 260 Zebrafish and reared in thirteen aquariums (20 fish per aquarium) for 12 days. Zebrafish was fed at different dose (4.0g; 6.0g; 8.0g.kg-1) and different type of extraction [noEDTA/noKCl; KCl; EDTA and (EDTAandKCl)]. The evaluation of radical scavenging activity was done spectrophotometrically at 515 nm. Results showed that the highest alginate yield either polysaccharide or oligosaccharide was gained from KCL treatments, percentage inhibition (82.61%), growth performance as well as tolerance of stress (P<0.05). The best growth performance was reached in oligosaccharide supplementation at 6.0g.kg-1 treatment. It can be concluded that alginate oliogosaccharide produced by thermal heating enhanced the antioxidant activity, boost the fish’s immune system, proofed by better growth performance and more tolerant to the low oxygen stress.