Stopping Winter Flooding of Rice Fields to Control Invasive Snails Has no Effect on Waterbird Abundance at the Landscape Scale

The invasive apple snail (Pomacea maculata) appeared in 2010 in the Ebro Delta Natural Park, an important area for rice production and waterbird conservation in the eastern Mediterranean. To control crop damage, farmers stopped flooding their rice fields in winter, an agri-environmental scheme (AES) applied for more than 20 years in some European and American regions to favor flora and fauna from wetlands, including wintering waterbirds. Thus, apple snail control is controversial because of its potential side effects on international waterbird conservation efforts. Despite the fact that 10 years have passed since the first flooding limitations, and the alarms raised by the managers of the Natural Park, the side effects of apple snail management on waterbird conservation have not been evaluated. Here we fill this gap by analyzing a 35-year time series to assess whether abundance trends of 27 waterbird species, from five functional groups, decreased in the Ebro Delta after stopping winter flooding. We considered the effects of confounding local factors by also assessing trend changes in l’Albufera, a similar nearby not invaded wetland where flooding has not been interrupted. In addition, as a control of the positive effect of winter flooding, we also assessed whether abundance trends increased in both wetlands after applying this AES winter flooding. Our results showed complex and decoupled trend changes across species and geographical areas, without statistical evidences, in general or for any particular functional group, on the positive effect of winter flooding in both wetlands neither on the negative effect of its cessation in Ebro Delta. These results suggest the safety of this apple snail control in terms of waterbird abundance at a landscape scale. In addition, these results question, at least in two important wintering areas in Europe, the attractor role associated with the flooding agri-environmental scheme applied for decades.

PENGARUH SUBSTITUSI DAGING KEONG MAS (Pomacea canaliculata L) DAN DAGING AYAM TERHADAP KARAKTERISTIK ORGANOLEPTIK DAN NILAI GIZI NUGGET

ABSTRACTThis study aimed to determine the effect of golden apple snail and chicken meat substitution on the organoleptic characteristics and nutritional values of chicken nuggets. This study used a single factor completely randomized design (CRD), with five levels of treatment, namely P0 (0% golden apple snail meat: 50% chicken meat: 50% wheat flour), P1 (45% golden apple snail meat: 5% chicken meat: 50% flour), P2 (40% golden apple snail meat: 10% chicken meat: 50% flour), P3 (35% golden apple snail meat: 15% chicken meat: 50% flour), and P4 (30% golden apple snail meat: 52% chicken meat: 50% flour). Data were analyzed using Analysis of Variance (ANOVA). The results show that the substitution treatment of golden apple snail (Pomacea canaliculata l.) and chicken meat had a very significant effect on increasing color, taste, aroma, and texture. The P1 treatment (45% golden apple snail meat; 5% chicken meat and 50% wheat flour) was the most preferred treatment by panelists with preference scores of color, aroma, texture, and taste reached 3.74 (like), 3.93 (like), 3.68 (like), and 3.68 (like), respectively. Meanwhile, the analysis of the nutritional values shows that the selected treatment contained 30.68% water, 2.44% ash, 10.24% fat, 9.04% protein, and 47.6% carbohydrates. Based on the standard of SNI 01-6638-2002, the golden apple snail and chicken meat nuggets met the quality standards on water, ash, and protein contents.Keywords: golden apple snail meat, chicken meat, nuggets.ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh subtitusi keong mas dan daging ayam terhadap karakteristik organoleptik dan nilai gizi pada pembuatan nugget. Penelitian ini menggunakan Rancangan Acak lengkap (RAL) faktor tunggal, dengan lima Perlakuan P0 (daging keong mas 0% : daging ayam 50% : tepung terigu 50%), P1 (daging keong mas 45% : daging ayam 5% : tepung terigu 50%), P2 (daging keong mas 40% : daging ayam 10% : tepung terigu 50%), P3 (daging keong mas 35% : daging ayam 15% : tepung terigu 50%) dan P4 (daging keong mas 30% : daging ayam 52% : tepung terigu 50%). Data dianalisis menggunakan Analysis of Varian (ANOVA). Hasil penelitian menunjukkan bahwa perlakuan Substitusi daging keong mas (pomacea canaliculata l.) dan daging ayam berpengaruh sangat nyata terhadap peningkatan warna, rasa, aroma dan tekstur.. Perlakuan P1 (daging keong mas 45%; daging ayam 5% dan tepung terigu 50%) merupakan perlakuan yang paling disukai panelis dengan skor penilaian kesukaan terhadap warna, aroma, tekstur dan rasa berturut-turut sebesar 3,74 (suka), 3,93 (suka), 3,68 (suka), 3,68 (suka), sedangkan berdasarkan analisis nilai gizi meliputi kadar air, abu, lemak, protein dan karbohidrat berturut-turut sebesar 30,68%, 2,44%, 10,24%, 9,04% dan 47,6%. Berdasarkan standar mutu SNI 01-6638-2002 produk nugget daging keong mas dan daging ayam telah memenuhi standar mutu pada kadar air, kadar abu, dan kadar protein. Sedangkan kadar lemak dan kadar karbohidrat belum memenuhi standar mutu SNI 01-6638-2002Kata kunci: daging keong mas, daging ayam, nugget.

Influence of Enzyme Concentration and Hydrolysis Time on Soluble Protein Content of Protein Hydrolysate Prepared from Apple Snail (Pila ampullacea)

The objective of this study was to evaluate soluble protein content of protein hydrolysates obtained by enzymatic hydrolysis of apple snail using a trypsin enzyme. Apple snail were collected from traditional market at Pabean-Sidoarjo. Trypsin enzyme was used in enzymatic hydrolysis. The two variables, enzyme/substrate (E/S) ( 0.01, 0.05, 0.1) ratio and hydrolysis time (3 h, 6 h, 9 h, 12 h, 15 h, 18 h) and was used to produce the apple snail hydrolysate. The result showed that soluble protein content was about 2.3%-4.52%. The increase E/S ratio and hydrolysis time, the higher soluble protein content values was. The highest total soluble protein was achieved E/S 0.1 ratio at 12 h, 4.52%. But, after 12 h hydrolysis time, soluble protein was decreased. Optimum treatment to hydrolyzing apple snail using trypsin enzyme was E3H4 treated (E/S 0.1 ratio and 3 h)

Analysis of Crayfish Catches Using Bubu Wau in Laut Tawar Lake, Central Aceh, Aceh

Laut Tawar Lake is located in the town of Takengon, Central Aceh district. Currently, Laut Tawar Lake has been utilized by the surrounding community as a fishing spot. One of the fishing gears used by fishermen is Bubu wau. One of the catches obtained by fishermen is crayfish. The crayfish has a high economic value, so the lack of control over the intensity of the catch also causes the average size of the crayfish caught, because catching crayfish is a transition from catching Rasbora tawarensis. One of the problems that frequently occur and research on crayfish has never been done before. Therefore, this research needs to be done. The purpose of this study was to determine fishing catch compositions of Bubu wau and the size distribution of crayfish carapace length of Bubu Wau fishermen in the Teluk One-one, Laut Tawar Lake. The research was carried out in about March 2021. The description of the fishing catch composition was analyzed by using the describded method. The size distribution of crayfish carapace length was analyzed by the Sturgess rule. From the results of the study, it can be concluded that the catch compositions of Bubu wau in Teluk One-one are crayfish, suckermouth catfish, channeled apple snail and tilapia. The type of crayfish caught by fishermen’s Bubu wau was Cherax quadricarinatus amount of 4232 individuals (89% of the total catch), where the total length of the dominant crayfish carapace was 4.4-4.9 cm with a total number of 1403 and the least with a size of 8.6-9.1 cm was 1 crayfish from the total catch

THE MOLLUSCICIDAL EFFECT OF THE STEM EXTRACTS OF Tinospora crispa IN CONTROLLING THE GOLDEN APPLE SNAIL Pomacea canaliculata

This study investigated the molluscicidal effect of the stem extracts of Tinospora crispa in controlling the golden apple snail Pomacea canaliculata. Extracts were prepared in four solvents, i.e., hexane, chloroform, methanol, and distilled water at three concentrations (1,000, 5,000, and 10,000 ppm) per solvent. The phytochemical contents of the extracts were qualitatively identified, and the lethal concentration (LC50) of the extracts for mollusicicidal potential was determined using the probit analysis. The effect of T. crispa extracts on the snail was monitored for three days and the snail mortality was recorded every 24 h. The stem extract prepared in methanol at 10,000 ppm showed the highest molluscicidal effect with a mortality of 80% at 72 h. Phytochemicals identified in the stem extracts included alkaloids, flavonoids, saponin, tannin, and terpenoids. Based on the probit analysis, stem extracts of T. crispa prepared in methanol showed the lowest LC50 value of 3,428 ppm for mollusicicidal potential and followed by extracts prepared in chloroform, hexane, and distilled water at 5,888, 14,771, and 14,993 ppm, respectively.

An Acoustic Treatment to Mitigate the Effects of the Apple Snail on Agriculture and Natural Ecosystems

Global change is the origin of increased occurrence of disturbance events in natural communities, with biological invasions constituting a major threat to ecosystem integrity and functioning. The apple snail (Pomacea maculata) is a freshwater gastropod mollusk from South America. Considered one of the 100 most harmful invasive species in the world, due to its voracity, resistance, and high reproductive rate, it has become a global problem for wetland crops. In Catalonia, it has affected the rice fields of the Ebre Delta since 2010 with significant negative impact on the local economy. As a gastropod mollusc it possesses statocysts consisting of a pair of sacs, one located on each side of the foot, that contain multiple calcium carbonate statoconia. This study shows the first ultrastructural images of pathological changes in the sensory epithelium of the statocyst of apple snail adults with an increase in the severity of the lesions over time after exposure to low frequency sounds. Sound-induced damage to the statocyst could likely result in an inhibition of its vital functions resulting in a potential reduction in the survival ability of the apple snail and lead to an effective mitigation method for reducing damage to rice fields.