Nekton

Quality Characteristics of Tuna Trim Surimi Patties with Added Carrageenan: Proximate, Sensory, and Physical Analyses

Muh Kasim — 2026-08-30

Tuna trim is a fishery by-product with potential for processing into surimi-based value-added products. This study evaluated the effects of κ-carrageenan concentrations (0.5%, 1.0%, and 1.5% w/w; two replications per treatment) on the proximate composition, sensory characteristics, and physical quality of tuna trim surimi patties. Proximate parameters, including moisture, ash, protein, fat, and crude fiber, were analyzed according to AOAC methods. Sensory evaluation was conducted using a 5-point hedonic scale for texture, taste, color, and flavor, while physical quality was assessed using folding and biting tests. Descriptive statistics were calculated for all parameters, and differences among treatments were analyzed using the Kruskal–Wallis test (α = 0.05) because the small number of replications did not meet the normality assumption required for parametric ANOVA. The results showed that carrageenan addition did not significantly affect any proximate or sensory parameter (p > 0.05). Moisture content ranged from 60.66–63.89%, ash from 1.88–1.94%, protein from 12.27–13.05%, fat from 0.145–0.207%, and crude fiber from 5.97–6.40%. Although the sensory differences were not statistically significant, the 1.0% κ-carrageenan treatment yielded the highest mean sensory scores and the best physical quality, achieving Grade A in the folding test and a chewy texture in the biting test. In contrast, patties containing 0.5% and 1.5% κ-carrageenan tended to break during physical testing. Therefore, 1.0% κ-carrageenan represents the most promising formulation for further development of tuna trim surimi patties.

Estimation of White Trevally (Decapterus macrosoma) Stock in the Waters of Nusa Laut, Maluku, Indonesia

Habib Harlino Rofi Latuconsina — 2026-09-03

The potential of marine resources from the Banda Sea, particularly the waters of Nusa Laut, represents an important economic aspect for local fishers. Several fishing fleets targeting scad, including mini purse seine vessels, are widely distributed in the area, with continuous exploitation activities occurring every week. This study aimed to analyze the growth pattern, mortality, and sex ratio of white scad (Decapterus macrosoma) in Nusa Laut waters, landed at Arumbai Market, Ambon. The research was conducted using a survey method from January to June 2025, with a total sample of 150 individuals. Data were analyzed based on growth pattern, fish mortality, and sex ratio analyses. The results showed that the asymptotic length (L∞) was estimated at 24.7 cm total length (TL), with a growth coefficient (K) of 0.61 year⁻¹ and a theoretical age at zero length (t₀) of −0.25 year. The fishing mortality (F) value was 0.46 year⁻¹, the total mortality (Z) was 1.80 year⁻¹, and the natural mortality (M) was 1.34 year⁻¹, resulting in an exploitation rate (E) of 0.25. The sex ratio analysis conducted from February to June indicated that the proportion of male and female fish was in a balanced condition, with a ratio of 1:1. Based on the exploitation analysis, the length corresponding to half of the asymptotic length (L∞/2 = 12.35 cm TL) indicated that the captured fish were still relatively small. Therefore, the biological characteristics of white scad caught in Nusa Laut waters, Central Maluku, and landed at Arumbai Market, Ambon City, indicate that the fish are predominantly captured at a small size with a relatively low exploitation level.

Distribution and Diversity of Coral Growth Forms at Different Depths in Badi Island, South Sulawesi, Indonesia

Samuel Alfaref Sembiring — 2026-09-14

Coral reefs are marine ecosystems composed primarily of calcium carbonate and characterized by diverse growth forms that reflect environmental conditions. Physicochemical factors, including water temperature, depth, and salinity, may influence coral growth and community distribution. This study aimed to analyze the distribution and diversity of coral growth forms and the physicochemical characteristics of the waters surrounding Badi Island, Pangkajene and Islands Regency, South Sulawesi, as baseline information for the inventory and assessment of coral reef ecosystem conditions. Data were collected in February 2019 at four stations established according to the cardinal directions at depths of 3 m and 10 m using the Line Intercept Transect (LIT) method. Benthic cover consisted of live hard corals (LHC), abiotic components, dead corals, and other fauna. Live hard corals were the dominant cover category, accounting for 59.38%, and were classified as good according to Decree of the Minister of Environment No. 4 of 2001. The most frequently observed coral growth forms at both depths were Acropora encrusting, Coral massive, and Coral encrusting. Coral growth-form diversity was classified as moderate, with H′ values ranging from 1.72 to 2.01, whereas the evenness index ranged from 0.44 to 0.52, indicating low evenness at three stations and moderate evenness at one station. Water quality was measured once at the surface layer at each station; therefore, the measurements represent conditions at the time of observation and do not capture temporal variability.