The issues faced by the Indian River Lagoon is quite similar to that of many rivers, lakes, and even oceans from various locations of the world. The steady decline in the marine population of the lagoon escalated to alarming rates by the end of the last decade. A few legislations that were passed in the early nineties to limit trawling in the estuarine region and as well as the direct dumping of untreated sewage wastes, had proved effective in the past. But later into the decade, the rescue efforts to salvage the lagoon and the ecosystem associated with it, has been deemed as fruitless after the unprecedented algal blooms of 2011 proved in the contrary. So the time has come to investigate for the core reasons that caused the alarming decline of marine organisms in the Indian River Lagoon (formed by three different lagoons, Mosquito lagoon, Banana river, and Indian river) as recorded from the year 2007 up until now.
After the algal blooms of 2011 and subsequent death of many lagoon species (such as seagrass) researchers were able to recognize the unique underlying compositions of the lagoon that was leading to such aftermaths. A few of them were the presence of 1.Excess nitrogen and phosphorus in the lagoon 2.Excess Septic tank seepage or leaks and 3.Nutrients released by muck formed from the biomass settled in the waterbed of the lagoon (also caused by erosion, construction, etc). Exponential algal growth in the lagoon caused the phenomenon called Eutrophication which is marked by the depletion of dissolved oxygen in the water. The following essay shall attempt to understand these issues in detail and suggest a possible remedy to manage or mitigate the risks associated with it.
Excess Nutrients and Issues
In most cases, eutrophication is a direct result of fertilizer run offs from cultivated farm fields. Even though septic tank effluents are far more superior in quantity, they are not as effective in causing this phenomenon as the nutrients from farmlands. The fertilizers used in the farm are intended to facilitate the rapid or superior growth of the plants cultivated in it. Most often the quantity as well as the concentration of the fertilizer mix is determined by the needs of the plant under cultivation. In any case, these requirements are utterly superfluous for the needs of a common algae. The direct result of this fact is that the run offs from large farm fields, as they are far more nutritious than what algaes need for their development, causes their exponential growth and depletes all or most of the dissolved oxygen along with it.
The second most detrimental human intervention that caused the depletion of the marine ecosystem in the Indian River Lagoon was the effluents from septic tanks. In the year 2013, it was estimated that more than a few hundred thousand septic tanks were located along the land mass surrounding the lagoon. Even though the discharge of untreated septic tank effluents were limited by law before the millennium (in the Indian River Lagoon) there are still no possible remedies to completely arrest their leakages (and subsequent lagoon pollution) to this date. This is why septic tank effluents are just as harmful to the lagoon as fertilizer run offs. Limiting the content of sewage wastes in the lagoon is therefore a priority.
The role of muck, mostly from settled biomass in the bottom of the ocean, in releasing nutrients is not uncommon in the case of water reservoirs. But due to the exponential algal growth in the region and subsequent death of seagrass, the biomass getting settled in the bottom of Indian River Lagoon is quite large. This triggers the chain reaction of further algae blooms and further death of seagrasses until all of the other plant species are completely destroyed. At this point, the lagoon might become much harder to salvage. It is essential that remedies to check biomass settlement in the bottom of the ocean need to be implemented with the same vehemence as implementing other rescue measures.
Arresting Fertilizer Runoffs
As explained earlier, fertilizer runoffs had outperformed every other sources of nutrients that caused the phenomenon of algal bloom in the Indian River Lagoon. It is essential that we implement measures to completely arrest their further release into the lagoon. Unlike what many may think, this is essentially a simple task that could be easily done with the minimum of resources. Some of the best solutions to avoid water running off from the farm lands into the lagoons is by 1.Building watersheds 2.Planting buffers 3.Cover crops and 4.Runoff capture and filtration. Fertilizer runoffs are not only harmful to the lagoon but also affects the profit returns of the cultivated land. This is why many farmers employ a watershed to collect water produced from irrigation (and natural rain) that collects nutrients from the soil. This will help in fixing the nutrients back into the soil.
Buffers are the various shrubs or small trees that can be planted around the cultivated field as a barrier. They can hinder the flow of runoff water and the nutrients dissolved in it. This method is somewhat effective in limiting the quantity of nutrients that flows into the lagoon. Another effective solution is to use cover crops which can help in fixing most of the nutrients back into the soil while avoiding water runoffs to a great extend. But considering the state of our lagoon, even the mildest quantity of runoff can have serious effects on the algae growth. In this regard, the quickest and most efficient solution is to use runoff capture and filtration. This technology is a combination of the aforementioned methods to arrest any water runoff from the farm field. And in addition, plants to treat phosphorus and nitrogen contents can also be implemented in integration with the filtration mechanism.
Widespread implementation of runoff capture and filtration is a time consuming as well as highly expensive process. Moreover, depending on the type of crop or the content of fertilizer, effective treatment mechanisms such as coagulation and flocculation (using chemical reagents) might also be required. Such techniques require the administration of an expert advisor to ensure that they are properly cultured. The initial costs of implementing and maintaining such techniques will be significantly higher than the financial loss cost by fertilizer runoffs. It is essential that farmers are given enough incentives, in the form of grants, to build such treatment plants. Also, creating legislations to make filtering of runoff water mandatory for farm fields (of certain area) is important. This will motivate farmers in utilizing available grants to implement such measures. And by educating farmers and public about the necessity of such measures and the role of legislation in implementing them we can considerably reduce the backlash that this venture might receive during the course of its implementation. As such, it is expected that the program would go uninterrupted with minimal opposition from critics.
As a resident of Brevard County it is essentially my responsibility to support steps undertaken to salvage our Indian River Lagoon from all the detrimental waste and sewage contents it suffers from. As such, I find the aforementioned runoff capture and filtration method highly beneficial. It is not only very easy to implement (with just a few help from Governments or environmental agencies) but also the best solution in arresting the most prominent source of excess nutrients in the lagoon. The method also helps farmers reduce the subsequent fertilizer requirements every year. For instance, if runoff filtration is implemented effectively, farmers can forgo the need for applying fertilizers for the next season as the filtration technique can effectively fix the nutrients back into the soil. Therefore, the benefits of this method are twofold 1.Saving the Indian River Lagoon and 2.Preventing the application of excess nutrients into the soil which may otherwise deplete it. Clearly, this is the best choice befitting our needs.
