Pengaruh Externalitas Pada Stuktur Biaya Produksi Biodiesel Mikroalga Sebagai Sumber Energi Ramah Lingkungan

Penelitian ini bertujuan untuk memperkenalkan biomassa mikroalga sebagai bahan baku biodieselalternatif yang ramah lingkungan. Perbandingan semua variabel biaya produksi antara mikroalgadan biodiesel kelapa sawit menggunakan proses produksi sistem analisis siklus analisis siklus hidupdiperpanjang (extended LCA) di evaluasi. Penggunaan sistem extended LCA dapat mencakupisemua variabel komoditas lingkungan sehingga potensi biomassa mikroalga sebagai materialyang terbarukan, rendah dalam penggunaan lahan dan berkelanjutan dapat dipromosikan. Nilai-nilai variabel komoditas lingkungan diperkirakan melalui pendekatan kesediaan membayar (WTP)menggunakan perangkat lunak yang di kembangkan oleh Strategi Prioritas Lingkungan (EPS).Hasil penelitian menunjukkan bahwa ada peningkatan biaya produksi biodiesel dari mikroalga danminyak sawit setelah dimasukkannya biaya variabel eksternalitas nya. Biaya produksi biodieseltertinggi berasal dari tahap segar produksi biomassa tandan buah kelapa sawit (49%-64 %) daritotal biaya. Analisis extended LCA menyimpulkan bahwa kenaikan mikroalga dan biaya produksiminyak biodiesel sawit adalah sekitar 2,6 % dan 17,7%. Biomassa untuk produksi biodiesel darimikroalga relatif lebih ramah lingkungan dibandingkan dari kelapa sawit karena berbagai kendalapada penggunaan mikroalga dapat ditangani. Selain itu, mikroalga memiliki kontribusi yang signifikandalam gas rumah kaca (GRK) mitigasi dengan mengganti bahan bakar fosil di masa depan melaluiperannya sebagai biodiesel

Algal bioremediation of waste waters from land-based aquaculture using Ulva: selecting target species and strains

The optimised reduction of dissolved nutrient loads in aquaculture effluents through bioremediation requires selection of appropriate algal species and strains. The objective of the current study was to identify target species and strains from the macroalgal genus Ulva for bioremediation of land-based aquaculture facilities in Eastern Australia. We surveyed land-based aquaculture facilities and natural coastal environments across three geographic locations in Eastern Australia to determine which species of Ulva occur naturally in this region and conducted growth trials at three temperature treatments on a subset of samples from each location to determine whether local strains had superior performance under local environmental conditions. DNA barcoding using the markers ITS and tufA identified six species of Ulva, with U. ohnoi being the most common blade species and U. sp. 3 the most common filamentous species. Both species occurred at multiple land-based aquaculture facilities in Townsville and Brisbane and multiple strains of each species grew well in culture. Specific growth rates of U. ohnoi and U. sp. 3 were high (over 9% and 15% day⁻¹ respectively) across temperature treatments. Within species, strains of U. ohnoi had higher growth in temperatures corresponding to local conditions, suggesting that strains may be locally adapted. However, across all temperature treatments Townsville strains had the highest growth rates (11.2–20.4% day⁻¹) and Sydney strains had the lowest growth rates (2.5–8.3% day⁻¹). We also found significant differences in growth between strains of U. ohnoi collected from the same geographic location, highlighting the potential to isolate and cultivate fast growing strains. In contrast, there was no clearly identifiable competitive strain of filamentous Ulva, with multiple species and strains having variable performance. The fast growth rates and broad geographical distribution of U. ohnoi make this an ideal species to target for bioremediation activities at land-based aquaculture facilities in Eastern Australia

The german case study: Pioneer projects of aquaculture-wind farm multi-uses

Most studies on multi-use concepts of aquaculture and wind farms explored cultivation feasibility of extractive species, such as seaweed or bivalves. However, recent studies also included the cultivation of crustaceans or fish culture in the vicinity of wind turbines. Consequently, new approaches combine fed and extractive species in integrated multi-trophic aquaculture (IMTA) concepts for offshore multi-use to reduce nutrient output and the overall environmental impact of aquaculture operations. In this chapter the findings of a series of mussel and oyster cultivation experiments over several seasons are presented, which were conducted at different offshore test sites in the German Bight. Sites were selected within future offshore wind farm areas for an explicit multi-use perspective. Results have demonstrated successful growth and fitness parameters of these candidates and therefore definitely proved the suitability of these bivalve extractive species for open ocean aquaculture. Another approach for multi-use in offshore wind farms is its use as marine protected area or even for reinforcement or restoration of endangered species, which need the absence of any fisheries activity for recovery. Current projects are testing this perspective for the native European oyster Ostrea edulis and the European lobster Homarus gammarus. From the technological point of view there are many options on how to connect aquaculture devices, such as longline and ring structures as well as different cage types, to the foundations as well as to install it in the centre of the free area between wind turbines. Next to the system design also experiments on drag forces originating from the aquaculture structure on the foundation and vice versa were investigated. Complementary to the biological, environmental end technical aspects, a number of studies were specifically targeted to address and include stakeholders, their attitudes, their interests and concerns over time. By this approach, the inclusion of stakeholders into the research process from its very beginning until today, co-production of knowledge could be fostered. Next to joint identification of the major impediments and concerns of offshore aquaculture under multi-use conditions, new issues and research questions were identified. Primary focus on the economic potential of aquaculture in offshore wind farms was shown for consumption mussels. The production of mussels using longline technology is sufficiently profitable even under the assumption of substantial cost increases. This is especially true, if existing capacities could be used. Last but not least, the EEZ is a special area-it is not a state territory even if a coastal state has its sovereign rights and jurisdiction. It is an area where three legal systems come together: International law, law of the European Union and national law. There are no mariculture projects in the German EEZ and no approval procedure has been completed so far. Some sites are not suitable for mariculture, especially because of nature conservation and shipping