TALE OF AN OCEAN: Oceanarium Complex at Sonadia

Military Institute of Science and Technology

Project idea

Sonadia Island, close to the Bay of Bengal, is a mix of microclimates with sand dunes, black mangroves, and a special estuary ecology that is impacted by tidal surges every day. Numerous animals live there, including over 50 vulnerable species. Due to local illegal usage of these places and environmental changes, the island experienced considerable losses; as a result, Environment Conservation Act of Bangladesh recognized it as an Ecologically Critical Area (ECA). Out of the 8300 acres of nature reserve, 900 acres will be developed for public use, and the government has proposed using 13.3 acres of this property for the Oceanarium complex. The project explores energy efficient, sustainable & lightweight construction methodology that can survive the complex climatic condition of Sonadia including poor soil conditions, salinity, daily water surges, seasonal cyclone. The challenge was to design a lightweight structure which can be easily assembled on site and can support the massive aquariums. Through conscious landscaping using local flora and fauna as a guideline, symbiosis is created between the architecture and nature which rejuvenates the natural ecosystem and provide safe crawling spaces for the local fauna. Lastly the goal is to facilitate research opportunities and create public awareness by exhibiting marine life in the aquariums and also in their natural habitat. The topography of the site is of three categories: Dry zone (usually dry), Semi-dry zone (prone to seasonal tidal surge), and Wet zone (due to regular tidal surge). There are three separate exhibitions-Salt water, Fresh water and Dolphinarium, an ocean heritage museum, research and service block, a public block and a cafeteria along the site.

Project description

The main objective of this project is to explore sustainable construction technology for Sonadia, an ecologically critical and complex area. To design a sustainable aquatecture which will protect the environment and is both aesthetically and volumetrically pleasing as an oceanarium complex, was challenging. This oceanarium works as a rescue and rehabilitation center for local endangered species. On the other hand, the research center focuses on the betterment of these species and conducts study means to protect the marine and mangrove ecosystem in collaboration with the local hatchery. Besides, the conscious landscaping allows local flora and fauna to co-exist within the aquatecture. The prime focus here is to rehabilitate local faunas and provide shelter to those with special needs. Rather than focusing on captivating local faunas, the goal is to create special attraction point for these faunas through planting trees consciously so that a natural exhibition is formed. There is presence of exotic fish tanks which primarily help educate people about marine life here. However, the main goal of the complex is to rescue marine life and provide outdoor natural exhibitions in contrast to the conventional aquariums. Here, the Dolphinarium has the capacity to accommodate two rescued local Dolphins in special need and also includes an outdoor open to sky crawling tank. The ground floor holds habitat tanks and medical tank(as per section AA’ and Ground floor plan).Dolphins tend to do well in open tanks in outdoor areas. In nature, they swim to the shallow shore areas for eating small fishes. A shallow pool here mimics this phenomenon with small fishes with opening routines at certain time of day for feeding purposes. There is a turtle pool with rescued turtles. These rescued fish and animals facilitate educating people about wildlife and about how they are affected in daily life. The daily population entry per hour is well controlled to protect the peace within the compound so that it does not affect the wildlife in the outdoor natural exhibitions.

Technical information

To address the salinity issue and daily tidal surges, Ferrock is used for the substructure construction, as conventional building material- concrete reacts to saline water. Ferrock is produced from 95% recycled material and is cost-effective. It’s a carbon negative and takes only 3 days to cure. The structural elements are modeled to allow these to be built off-site and then assembled in site within a limited period of time. Ferrock doesn’t react to saline water and is more resilient than concrete, which makes it a good material for this type of climatic condition. For the superstructure, double layered ETFE panels are used with integrated photovoltaic cells. ETFE cushions are self-cleaning, low maintenance, cyclone resilient material- safe from any type of fire hazard for its self-extinguishing qualities. It doesn’t produce any glare or doesn’t increase outdoor temperatures. Which makes it safe for birds -a very important thing to consider in such site which is a home to different endangered birds. The double layered ETFE cushions decrease the indoor temperature up to 5 degrees Celsius that in the long run decreases overall cooling load and energy consumption. The layered system facilitates to control the amount of light that would be allowed in the indoor environment. This will reduce the need for indoor lights in daytime. Again, during night, the indoor lights can penetrate through the panels-reducing the need of outdoor lights. Each aquarium dome is self-sufficient-uses solar power, produces its own water, is cyclone and saline water resilient -which makes it a site responsive prototype that can be installed in this type of areas. The materials used are low maintenance, cost effective and environmentally sustainable. The solar powered dome will be able to produce 65-70% of its daily electricity needs based on the weather and sun exposure. Again, the structure is elevated considering future sea level rise. If the sea level rises more than the future prediction, most of the materials can be demounted and reused because of its modular properties. The modular properties also allow easier transportation even using waterways. All these materials are lightweight than the conventional materials like concrete, glass-which makes it feasible for this type of loose mangrove soil quality.
Service routes within the complex is managed by maintaining an independent service loop at different levels from entrance to the Service block. Internal moving cart will be used to provide maintenance and cleaning services within the complex. Emergency exits have been ensured from each domes maintaining the BNBC Law. There is a Desalination pod at the core structure of each aquarium mass. Like the central gastrovascular cavity of sun coral, the desalination pod integrated with rainwater harvesting channels are responsible for the main water circulation system of the site. The desalination pod uses solar energy to turn saltwater into fresh, drinking water and commercial salt brine. It uses Solar power to operate. During tidal surge the saltwater is collected through sea water inlet pipe and sprayed through a nozzle in the desalination chamber. Solar power is used to increase the temperature in the chamber which allows the water to evaporate. Evaporated water condenses naturally while going through the condensation pipe. The water is then stored at the bottom of the core for further use in freshwater aquarium and to provide freshwater for the site. The brine is collected and primarily processed in the service block and supplied to local salt production factory. It brings in many environmental and financial benefits. The local brine collection method from the sea is unhygienic and brine is stored directly on ground using embankment. This process increases the salinity of the area for a certain time drastically-which directly affects the mangrove ecosystem, because the pneumatophores of the mangrove trees can withstand a very limited range of saline level. It was reported that, due to this, the mangrove of Senaida was dying, and the mangrove soil was turning black for excess soil contamination through salt. By integrating the desalination pod in the masses-it will eventually eliminate the first step of local brine collection from the sea and save the mangrove from any further harm and restore it. In this case of water desalination, the dominating current alternatives capable of desalinating water only recover a fraction of the water and dump the rest, which is harmful, back to the sea. This system, on the contrary, evaporates 100% of the water, recovering the solutes, following a full waste-to-money philosophy. It spends 75%-95% less energy than conventional thermal systems, spends 50% less energy than reverse osmosis, and reduces costs by 75% in contaminated water desalination. It deals with water shortage through sustainable solar distillation and is low maintenance. Again, due to the use of double layered ETFE Cushions integrated with solar panels-It would even work during cyclones even when the main electricity power is cut out-and will be able to provide freshwater after the cyclone. The domes are elevated considering the max level of storm surge. The ETFE cushions used in the domes are resilient to the maximum windspeed recorded during cyclones in this area, thus the dome can be used as cyclone shelter because of its resiliency and independency in terms of providing the basic needs like water, electricity and hygiene.