Kontribusi Ekosistem Mangrove Terhadap Produktivitas Primer Perairan Pesisir di Kawasan Beejay Bakau Resort Probolinggo

Abstract

Probolinggo City is a coastal area with a mangrove area of about 90 hectares, located close to the Coastal Fishery Port (PPP) Mangunharjo Village, Probolinggo City. The mangrove ecosystem in this area was previously a waste disposal area with degraded mangrove conditions, then managed and rehabilitated into a tourist attraction under the name Beejay Bakau Resort (BJBR). Rehabilitation of the mangrove ecosystem can maintain the balance of the ecosystem by maintaining the supply of nutrients around it. The recovered mangrove ecosystem will produce more litter, which becomes a source of nutrients for the ecosystem. The nutrient content and abundance of plankton is one indicator for water productivity. This research was conducted in December 2020 in the BJBR mangrove ecosystem, Probolinggo. Determination of research stations using the purposive sampling method. Data collection of mangrove vegetation and environmental characteristics was carried out using the quadratic transect method. Water samples were taken at high and low tide and then analyzed for nutrients and plankton. Variations in environmental characteristics between research stations and the abundance of plankton between stations and environmental conditions were analyzed using Principal Component Analysis (PCA). Furthermore, multiple linear regression analysis was performed to determine the relationship between chlorophyll-a and dissolved nutrients. The results showed that the mangrove ecosystem of BJBR, Probolinggo has three mangrove species, namely Avicennia marina, Rhizophora stylosa, and Rhizophora mucronata. Mangrove density in this ecosystem varies, with dense density for the tree category, moderate for the sapling category, and medium-rare for the seedling category. The concentration of available P ranged from 37.00-69.32 mg/kg, the concentration of C-organic ranged from 1.30-2.61% and the concentration of N-total ranged from 2.57-4.80%. The estimation results using multiple linear regression showed that nitrate and orthophosphate significantly affected the chlorophyll-a concentration of 68.6% (F= 37.22, P=0.007). Phytoplankton found in the waters of the BJBR ecosystem consisted of three classes of phytoplankton, namely Bacillariophyceae, Cyanophyceae, and Dinophyceae, with the highest abundance were the class Bacillariophyceae. The zooplankton found consisted of the Protozoa, Crustaceae, Urochordata, Pelecypoda, Gastropods, Nematodes, Polychaeta, and Coelenterata groups, with the highest abundance in the Crustaceae class. The results of this study are expected to be used for management policies of BJBR's mangrove ecosystem based on fishery resources.