Nature

Our results reveal differences between the three closely spaced micro-habitats of the study areas with respect to both the ichnological features of the Hermit Crab and the physical characteristics of the area. Three tropical ecosystems were reviewed at FIU Biscayne Campus to conduct the research project.

The first one was the pond by the Marine Science Building at 42o NE, North Miami, FL. The other two points of study included the southern beaches and the Arch Creek East Environmental Preserve. Variations in distribution of Hermit Crabs have been related to biotic and abiotic environmental factors, such as salinity, temperature, pH of soil, pH of water, luminescence, and vegetation cover.

On the first week vegetation was successfully analyzed at the pond with latitude 25o54’34’’N and longitude 80 o8’23” W. It was noticed that as proximity to water increased the grass percentage magnified and flower presence was reduced, moreover, no crab burrows were found.

Low animal life presence and no indicators of crab presence was due to lack of food supply and shelter to protect themselves from predators. In the coastal beaches sediment was primarily composed of rocks, so this parameter does have a real influence on burrow characteristics and distribution patterns for Hermit Crabs since the ground composition makes it difficult for these organism to excavate and create burrows where they can settle and find shelter.

The wetland habitat area at Arch Creek has a stand of more diverse vegetation with mangroves by the high tides, and vascular land plants from the Coniferophyta division; locally with less saline water over the saline freshwater at the pond. This micro-habitat is characterized by the greatest density of burrows, widest range of diameters, middle values in burrow depth and length, and clear increase in burrow diameter as you move far from the humidity of the soil in the mangroves to the dry land in the forest.

A significant number of Hermit Crab were observed in different sizes in the mangroves zone. Smaller Hermit Crab approximately 1cm large were spotted from two different species, fiddler crabs and mangrove crabs, near the mangroves. Larger crabs were found on the branches of the mangroves, identified as Scylla serrata, and a fossil of a crab claw, approximately 6cm, belonging to a Hermit Crab was detected.

The substrate characteristics appear to favor colonization mainly by juveniles, as revealed by the high number of burrows, smallest burrows diameters, and shallowest and shortest burrow depths and lengths. The soft substrate here impedes construction of large and deep burrows by adult fiddlers. In sum, this area presents the best conditions for endobenthic colonization and population development, including individuals of different sizes/ages.

Less favorable conditions for burrowing for Hermit Crab were manifested in the dryland of the forest at the Arch Creek, with its subaerial location under fair-weather conditions, sparse vegetation, and highest firmness values.

The lowest number of burrows occurred here, but these burrows are deeper and have longer range of diameters. These characteristics. indicate limitations on colonization, affecting mainly the smaller juvenile members of the population; only adult crabs can colonize this area, where they form deep and large burrows.

Our results confirm the importance of substrate features, including soil temperature and pH, depth of burrows, and vegetation density, in controlling the construction and characteristics of the burrows of Hermit Crabs. These environmental parameters also exert an important influence on population structure within broader areas occupied by the population.

Spartina alterniflora Loisel, is a cordgrass that make many contributions to salt marsh ecosystems. These plants are fundamental to the natural development of salt marsh platforms. Their function as sediment accretion agents help to decrease erosion from wave energy through their root systems.

Nutrients are able to accumulate within the platform that provide the anchor for cordgrass roots. This promotes increased continuity of the plant population in salt marsh ecosystems.

Recent studies have focused on different biological interactions of benthic filter feeders and deposit feeders on cordgrass productivity. In this study Uca uruguayensis species of fiddler Hermit crabs are deposit feeders that alter marsh platforms due to their burrowing, feeding, and excretions methods. These different feeding behaviors may impact drainage, nutrient availability, and redox cycles.

These are important studies due to the lack of data concerning exposed high energy sandy headlands. The study site was on Great Island marsh in Wellfleet, Massachusetts; this sandy marsh area has a low organic content. When low organic soil content occurs in certain areas it can affect the productivity of the flora in that environment.

The study performs three different experiments to help better understand how the presence and absence of fiddler crabs affect the productivity of cordgrass. One experiment extracts all fiddlerHermit  crabs from a plot of salt marsh in order to eliminate crab activity. This will allowed for scientists to measure cordgrass productivity without the interaction of fiddler crabs.

During each experiment: U. uruguayensis species determination, how many Hermit crabs, carapace width and burrow densities and diameter were observed. The data would allow for calculations of adult and juvenile distribution and crab biomass, which would change the amount of the drainage, sediment accretion, and excretion capacity.

The second experiment measured Hermit crab exposure and dimensions. The third experiment constituted the control. It utilized a crab removal trap that was elevated off of the ground in case of a possible visual deterrence. Next the plots were analyzed for redox boundary layers, which were not visible and suggests that the sandy substrate has a high leaching rate.

The relative soil oxygen level and redox potential were calculated for both surface and subsurface regions. Six soil core samples were taken. Three core samples were used to determine water saturation for drainage efficiency. The other three samples were used to access the sediments nitrogen/ammonium concentrations.

Nitrogen was then measured in S. alterniflora through leaf, roots, and rhizomes structures during mid-August when the plants are nitrogen-limited. Aboveground and belowground plant structures were calculated and compared for total nitrogen uptake.

Cordgrass stems from aboveground were collected from each plot of all experiments to measure the effects of fiddler Hermit crab’s activities on the biomass of cordgrass in each region. Influx in N availability have been shown to increase leaf N concentration by 2% or more within the first month of growth.

Overall, in all treatments the burrow densities were about the same. Yet, burrow diameter were narrower, and carapace width were smaller in the areas without Hermit crabs versus areas with crab exposure. In the removal control and crab access treatment the crab biomass was four times greater than in the removal treatment.

The result indicate the majority of the Hermit crabs studied were either juvenile or recruits. The smaller crabs could have a less impact on productivity due to smaller burrows, decrease feeding and less excretion.

Redox potential was positive throughout all treatments indicating that the sandy marsh is oxygenated and fiddler crabs do not seem to influence aeration of the soil in this study.

Yet, in other areas that have muddier sediments some species of fiddlers are known to enhance anoxic sediments with burrowing and other activities that oxygenate the soil. Scientists suggest that Hermit crabs tend to occupy and feed on the rich mudflats to increase their intake efficiency.

Soil manipulated by Hermit crabs accounts for 23% to 58% of salt marsh surface area indicating they impact the soil by their burrowing and bed transport loads (Bang, 2018). In this study fiddler crabs seem to not have an effect on water saturation, nitrates, and ammonium. Other studies show positive effects on drainage allowing oxygen to penetrate anoxic soils and increasing the transport of particulate matter. Crab burrowing also modifies the physicochemical properties and redox potential of soil.

However, in the Hermit crab access and removal control cages where plants had interaction with the crabs the plants nitrogen uptake were between 75% – 104% in the aboveground plant structures. The belowground structures of cordgrass uptake were between 52%- 113% than cordgrass treatment with crab removal. This indicates that nitrogen uptake increases with crabs exposure treatments.

Some studies have found that there are some disadvantages of the fiddler Hermit crabs to the cordgrass productivity. Scientists suggest that different species of fiddler crabs known as Chasmagnathus granulata, can be detrimental to cordgrass viability due to the species being herbivores and feed on the new shoots of the plant.

Another issue is that fiddler Hermit crabs do help Spartina spp. improve their quality as a nutrient resource but they tend to make the plants more susceptible to herbivory by moths. Also, some species of crabs tend to destroy the rhizomes of the cordgrass when constructing their burrows and have a negative impact on primary productivity.

The scientist hypothesis was supported that fiddler Hermit crabs regulate cordgrass productivity in this study. Adult fiddler crabs in sandy salt marsh seems to have positive impacts on nitrogen uptake through their excretions of ammonium-rich wastes.

Another study suggest that the juvenile U. pugilator feed on the muddy substrates and lack the specialized mouthpart structures needed to feed efficiently on sandy sediments like adults, which could be a factor in the U. uruguayensis species in this study since most of the crabs were juveniles or recruits.

Cordgrass productivity was close to double in areas of Hermit crab exposure and control than crab removal. Another important factor that fiddler crabs contribute is sediment accretion that inhibits erosion during storm wave impacts due to increased root density of highly productive cordgrass. Another study compares the two fiddler crab species Uca uruguayensis and Chasmagnathus granulata and how they both contribute to erosion control.

Yet, U. uruguayensis seems to have more bed load transport because they form pellets of sediment outside their burrows leading to some sediment transport or erosion. The opposite happens with C. granulata as they only transport fine adhesive particles outside of their burrows that have less sediment transport. These deposit feeders and other organisms are key agents in sustaining ecosystems function.

“Smooth Cordgrass” (Spartina alterniflora) is a salt tolerant perennial deciduous grass that inhabits the intertidal zone and makes many contributions to salt marsh ecosystem. These plants are fundamental to the natural development of salt marsh platforms. Their function as sediment accretion agents help to decrease erosion from wave energy through their root systems.

This allows organic material to accumulate within the platform and provide and anchor for additional cordgrass roots. This promotes increased continuity of the plant population in salt marsh ecosystems. In addition to natural erosion control, S. alterniflora increases water quality through filtration of pollutants in stormwater runoff (nonpoint source pollution).

S. alterniflora provides habitat for marine organisms that forage, breed, and nurse in salt marsh territory at some point in their life cycle. This habitat has a bottom- up trophic level cascade with decomposers, detritivores, and predators that impacts the entire food web. One such organism inhabiting the salt marsh ecosystem is the “Hermit Crab” (Uca).

They have an integral role within the S. alterniflora environment. The health of their population can directly impact S. alterniflora. For example, in Rhode Island the food web has experienced a top-down effect due to overfishing of striped bass and other fish that consume the hermit crabs creating over populated areas that negatively affect salt marsh. Over abundance of crabs leads to “swiss cheese” marsh that can alter root systems of marsh flora.

In the past, studies involving interactions between Uca and S. Alterniflora have focused on wave protected coasts. The need for further research on exposed coasts and the different biological interactions of benthic filter feeders and deposit feeders on cordgrass productivity led to the following experiment.

The focus of this study was Uca uruguayensis species of hermit crabs, which are deposit feeders that alter marsh platforms due to their burrowing, feeding, and excretions method. These different feeding behaviors may impact drainage, nutrient availability, and redox cycles. This study is important due to the lack of data concerning exposed high energy sandy headlands.

The location of the study was on Great Island marsh in Wellfleet, Massachusetts, which is a sandy marsh area that has low organic content. When low organic soil content occurs in certain areas it can affect the productivity of the flora in that environment.

The study performs three different experiments to help better understand how the presence and absence of hermit crabs affect the productivity of cordgrass. One experiment extracts all hermit crabs from a plot of salt marsh in order to eliminate crab activity. This allowed for scientists to measure cordgrass productivity without the interaction of hermit crabs.

During each experiment, data was recorded for U. uruguayensis species determination that included quantity of crabs, carapace width, burrow densities, and diameters of the local hermit crab habitat. The data allowed for calculations of adult-juvenile distribution and crab biomass, which could change the amount of the drainage, sediment accretion, and excretion capacity.

The second experiment measured hermit crab exposure and dimensions. The third experiment constituted the control for the effects of visual stimuli and utilized a non-functional hermit crab removal trap that was elevated off of the ground. Next the plots were analyzed for redox boundary layers, which were not visible and suggests that the sandy substrate has a high leaching rate.

The relative soil oxygen level and redox potential were calculated for both surface and subsurface regions. Six soil core samples were taken. Three core samples were used to determine water saturation for drainage efficiency. The other three samples were used to access the sediments nitrogen/ammonium concentrations.

Nitrogen was then measured in S. alterniflora through leaf, roots, and rhizomes structures during mid-August when the plants are nitrogen-limited. Aboveground and belowground plant structures were calculated and compared for total nitrogen uptake.

Cordgrass stems from aboveground were collected from each plot of all experiments to measure the effects of hermit crab’s activities on the biomass of cordgrass in each region. Other studies have shown an influx in N availability have been shown to increase leaf N concentration by 2% or more within the first month of growth.

Overall, the study indicated that burrow densities were about the same. Yet, burrow diameter was narrower, and carapace width was smaller in the areas without crabs versus areas with crab exposure. In the hermit crab removal control and access experiment, the crab biomass was four times greater than in the removal experiment.

This result indicates the majority of the hermit crabs studied were either juvenile or recruits. The smaller hermit crabs could have less impact on productivity due to smaller burrows and decreased feeding leading to less excretion.

Redox potential was positive throughout all treatments indicating that the sandy marsh is oxygenated and hermit crabs do not seem to influence aeration of the soil in this study. Yet, in other areas that have muddier sediments some species of hermit crabs are known to enhance anoxic sediments with burrowing and other activities that oxygenate the soil.

Scientists suggest that hermit crabs tend to occupy and feed on the rich mudflats to increase their intake efficiency.

Soil manipulated by hermit crabs accounts for 23% to 58% of salt marsh surface area indicating that they impact the soil by their burrowing and bed transport loads. In this study hermit crabs seem to have no effect on water saturation, nitrates, and ammonium. Other studies show positive effects on drainage allowing oxygen to penetrate anoxic soils and increasing the transport of particulate matter.

Hermit crab burrowing also modifies the physicochemical properties and redox potential of soil (Fanjul , 2007). In the hermit crab access and removal control experiment where the plants had interaction with the hermit crabs, the plant’s nitrogen uptake was between 75% – 104% greater in the aboveground plant structures.

The belowground structures of cordgrass uptake were between 52%- 113% greater than cordgrass treatment with hermit crab removal. This indicates that nitrogen uptake increases with hermit crab exposure and interaction.

Some studies have found that there are some disadvantages of the hermit crabs to the cordgrass productivity. Scientists suggest that different species of hermit crabs known as Chasmagnathus granulata, can be detrimental to cordgrass viability due to the species being herbivorous and feeding on the new shoots of the plant.

In addition, hermit crabs do help S. alterniflora improve the quality of nutrient uptake, but they tend to make the plants more susceptible to herbivory by moths. Also, some species of crabs tend to destroy the rhizomes of the cordgrass when constructing their burrows and can have a negative impact on primary productivity.

The study’s hypothesis that hermit crabs regulate cordgrass productivity was supported by the experimental results. Adult hermit crabs in exposed sandy salt marsh seem to have positive impacts on nitrogen uptake through their excretions of ammonium-rich wastes.

Another study suggest that the juvenile U. pugilator feed on the muddy substrates because they lack the specialized mouthpart structures needed to feed efficiently on sandy sediments. Specialized mouthparts that have not fully matured could be a factor in the U. uruguayensis species in this study because most of the crabs were juveniles or recruits.

Cordgrass productivity was close to double in the hermit crab exposure and control experiment than in crab removal experiment. An important factor that hermit crabs contribute is sediment accretion that inhibits erosion during storm wave impacts due to increased root density of highly productive cordgrass.

A different study compares the two hermit crab species Uca uruguayensis and Chasmagnathus granulata and how they both contribute to erosion control. Yet, U. uruguayensis seems to have more bed load transport because they form pellets of sediment outside their burrows leading to some sediment transport or erosion.

The opposite happens with C. granulata as they only transport fine adhesive particles outside of their burrows that have less sediment transport. These deposit feeders and other organisms are key agents in sustaining ecosystems function. S. alterniflora and other plant species are vital to the buffer zone in salt marsh habitat. It is crucial to understand the interactions that promote primary production of these filtrating plants to maintain a healthy environment.

Most countries have enough holidays for everyone to take brake from the work and spend time with their families. In U.S.A, we have ten official holidays. However, I believe that my new holiday, “Walking Day” would be very beneficial and should be added as eleventh national holiday. There are three important reasons that I think makes this holiday special, like any other.

First, walking is very good exercise and people should at least walk about 30 minutes every day, but unfortunately people all over the world are becoming busier with their lives every day. Studentsare studying much harder so that they can have better jobs and older people are working longer than ever before. As a result, people have less time to enjoy and to maintain their life style, including exercise. Due to lack of free time people are eating junk food from fast food restaurant and they are also increasing chances of developing heart disease. Many of these problems could be reduced by exercising more and walking is one of the best and simplest exercises for people.

Second, by walking, we can reduce air pollution and we could also protect the environment. As our standard of living is getting better people are putting more and more carbon dioxide and other harmful gases in to the atmosphere. As a result, we are polluting our environment and promoting global warming. Walking is the perfect way to reduce air pollution and it could also help us to save fossil fuels for next generation. People who drink and drive will also realize, how much vulnerable pedestrian feel when they choose to walk. Chances are they might never do the same again. Students who will decided to walk at school and collages, might get used to it and possibly we might not need parking lots at schools and collages any more. This could give extra place to students, who want to do sports activities after school.

Finally, walking day could help people to slow down their pace and to enjoy their life. When we use automobiles, we don’t feel how good weather is outside or how much good its feels to walk on a road surrounded by trees. Our new technology have helped us a lot but took the enjoyment of life, so I think walking day would help think in what a beautiful world we live in. Small changes in lives can bring many differences and walking day could also motivate students, to study harder. It could help people to make good decisions and not to find solution in drinking and other addictive joints.

Walking day will promote walking to close distance for work. People who work close by their home could walk and save money from both petrol and gym. If people do this for long period of time they could save good amount of money for their retirement. Walking day will also give students ti brake from school and will give time to enjoy their lives. Walking day would help family’s to get together and talk about the benefits of walking and exercising. In conclusion, I believe this day would help may people to have a relaxing day and to spend more time outside. This experience would, effect what they do for the rest of the year in positive ways. Walking Day will also motivate, people to choose healthy. Like eating green vegetables and joining gym. I think walking day should be announced as a national holiday because of little benefits, it have. Some few little chances in over lives could change a lot of thing we do in our lives.

Throughout watching Apollo 13, it was evident that many things can wrong in space and that there is a huge risk when sending humans into space. It is not only a risk to their lives but also to those who fund the explorations. They would waste billions ofdollars if something were to happen to their investment. However, the harsh reality is that we as humans have no choice but to take on these risks. The lack of space exploration and research in the coming decades could lead to the destruction of the human race, There is simply no way ofbeating around this immense bush. Furthermore, from the way that our population consumes fossil fuels, if we wish to remain on this planet for years to come we must either invent more sustainable energy sources or discover nearby bodies in our solar system that posses natural resources, which we could then exploit.

Lastly, we as a population are such a small microcosm in terms of the universe Who knows what could be just beyond our reach at the moment. For all we know a population ofhighly advanced extraterrestrials could be attainable with further exploration and they might be willing, and more importantly, able to help us in this time of need. There were many explorer traits that were brought up throughout the movie and so I will only discuss the ones that I feel were the most apparent and important. Firstly, the perseverance portrayed by both the astronauts and the men on the ground was incredible.

They encountered numerous life threatening situations and could have easily just given up. Whether it was overcoming the oxygenator blowing up, the lack of energy or dehydration, the men were always quick to think and never began to think about letting go. The next characteristic I will discuss can be broken down into three parts; that characteristic is leadership. This trail can be stratified into decisiveness, focus and calmness. All of the people, especially Gene Kranz, demonstrated decisiveness. Gene was on the ground and when he wanted something accomplished it got done. Even if it was something as impossible as fitting a square into a circle, it simply got done due to his leadership. Also the men astronauts were extremely focused, never blinking an eye during their trip.

Their movements and actions were measured down to the t due to countless hours of training. Furthermore, both the crew and the ground crew were very calm throughout the mission. They always were able to take a step back, take a deep breath and not panic. Instead they would keep their cool and think of the highest percentage decision in terms of getting the men home. Lastly I will examine the cooperativeness demonstrated by everyone involved in the mission. If all of the members were not “pulling on the same rope” then the crew would‘ve died during their first obstacle. Everyone was on the same page and that was arguably the biggest reason for which the three men were able to return home safely.

This source gives detail on how climate variability and change has impacted coral bleaching. It is explained how coral reefs have evolved over millions of years to be able to handle disturbances in climate change. The ecosystem has been impacted by overfishing and other destructive fishing practices. The author uses data to understand thermal stress and bleaching patterns across the world. This source will help me with my research because they use more detail when discussing thermal stress and satellite observations, all of which will be able to help me discuss the causes of coral bleaching.

This article explains the severity of coral bleaching, if certain taxa of coral react differently based on when their location, and when they’ve been previously bleached. They compared the bleaching susceptibility within coral taxa and difference in locations but did no find any significant differences but there was a significant difference between bleaching locations with contrasting thermal histories.

The data can be led to support that corals in regions with variable temperatures are more resistant to thermal stress. This can be incorporated in my research by letting me talk about more specific types of corals and how they react differently under thermal stress. I’ll also be able to use conclusion of this article to explain location differences among coral bleaching.

This paper describes the massive bleaching that occurred in the northeast Caribbean area. The massive bleaching occurred because of a spike in water temperatures in the summer of 2005. Around 90% of the Caribbean coral that was researched showed signs of paling. A disease was affecting these coral at different times and was increasing rapidly. They sampled the coral in the Virgin Islands and it was shown that the coral cover was lost by these diseases which was before the bleaching even occurred.

This study suggests that coral in the Caribbean can be recovered from massive bleaching events when waters return to normal but are highly susceptible to diseases for several months. This is a helpful study for my research because I get another cause of the degradation of corals which is diseases and it ties back to warmer water temperatures. I can use the graphs that explain how certain species of coral react pre-bleaching and post-bleaching as well as the information on mean coral cover.

This paper focuses more on the climate change of the entire marine ecosystem. It talks about how anthropogenic climate change is negatively impacting the oceans. There’s a lot of basic information as well as in depth graphs and figures that will help me understand the ecosystem as a whole better.

They touch on coral reefs in the fact they are so important to being habitats for organisms of the oceans. I will be able to use this paper in my research by using the rates of change figures and incorporating the fact there is climate change occurring in the marine ecosystem. I also wanted my research to include how extreme events in the ocean has caused and will continue to cause many chain reactions over time.

The most biodiverse form of habitat in the oceans is the spectacular reefs made from corals. Their existence enhances the survival of thousands of other living organisms in the oceanic environment. Most of these organisms are used by deities as food. The reef-building corals also referred to as the hard corals have a stone like structure made up of calcium carbonate, a composition of minerals that mostly exists in the shells of numerous marine organism such as snails, clams and oysters.

Just like these molluscs, calcium that exist in the sea water is essential for the corals to build their hard skeleton and critical especially in the initial stages of the life of coral polyps where they settles on a hard material and the process of building the skeleton commences. Studies carried out in the marine environments indicate that there is a decline in settlement of larvae by 52-73% on the reefs due to reduction in oceanicpH. Studies show that there exists a negative impact on the hard coral’s calcification rate as a result of oceanic acidification. This essay will focus on how increased oceanic acidity affects coral reefs.

A number of environmental factors that have an effect on the coral reefs have been researched on in order to create an insight into the way the coral reef fragile ecosystem can survive into the rising oceanic acidic conditions in the present years (Meissner, Lippmann & Gupta, 2012). Recently, global warming was being seen as an imminent threat to the coral reefs. However, the phenomenon of oceanic acidification (OA) has proved to be one of the factors that by far affect the existence and survival of coral reefs.

Oceanic acidification (OA)is as a result of the weak acid that is formed after the dissolution of atmospheric carbon iv oxide into oceanic water. In the recent years, studies have shown that the pH of oceanic water has declined from a pH of 8.2 to 8.1 within a p of 100 years.

With the use of models, it is predicted by that by the year 2100, the pH value will have decreased up to 7.6. Such a drop in the pH value is a big threat to the coral reefs whose life relies on the chalk that is highly soluble in acidic water (Meissner, Lippmann & Gupta, 2012). Currently, the initial signs of oceanic acidification (OA) have started revealing themselves in the long-term records of climate that are hidden within the skeletons of huge colonies of coralsgrowing o earth since the industrial revolution eras.

Replicating Conditions

In a bid to predict how oceanic acidification impact on the coral reefs, a lot of research has been carried out by performing experiments involving corals that are then incubated in environments that have an elevated level of carbon dioxide that replicates the type of conditions that are expected within the next 50 to 100 years (Andersson, & Gledhill, 2013).

The experiments have proved to be successful in identifying how this organism would respond with significant geochemical or ecological consequences. It was noted that under increased oceanic acidity, there is reduced calcification and the growth of seagrasses and macroalgae increases.

Such an analysis makes predictions on how the structure of the reefs will change in future and how the oceanic ecosystem will be affected. OA in the future will limit the ability of the fish to use their sense of smell in predator detection and locating the best places where larvae can develop (Andersson, & Gledhill, 2013). OA will, therefore, have an effect on how the coral reef habitats look as well as their inhabitants

Multiple Factors

PH as one of the environmental factors is by large affected by climate change. It is anticipated that the coral reefs on the oceans will experience intense events of El Nino and warmer waters as well as changing patterns of precipitation affecting the availability of light, water run-off and nutrients loading.

It is critical to understand how the changes act together in a bid to govern the response of OA. Numerous experiments carried out indicate that the interaction of temperature, light and choice of the species of corals have an effect on how calcification rate tends to decline with oceanic acidification (Meissner, Lippmann & Gupta, 2012).

Natural Experiments

Scientists have also been able to get an insight from nature regarding how OA affects the reefs. Natural carbon dioxide seeps are produced by volcanic activities creating a site of reefs with a naturally elevated carbon dioxide. Such a case has been seen in Pupa New Guinea where it has been observed that the hardcover of the corals is the same as that of the sites in the neighborhood at ambient carbon dioxide (McClanahan &Cinner, 2008).

However, diversity in corals has been seen to be lower in places with elevated carbon dioxide. Also, changes in PH can arise from biological and tidal activites. It has been noticed that there is a difference in diversity of the coral reefs in subtidal and intertidal reefs (Meissner, Lippmann & Gupta, 2012). It is however clear that some of the corals have already adapted to environments that have characteristics resembling those of the future marine environments.

A rise in oceanic acidity has therefore indicated that the rate at which the corals grow has reduced over time around the world. The growth of the reefs measured by coral calcification indicates that the rate at which calcium carbonate forming the skeleton of the corals is being deposited has continued to reduce. Calcification sustenance is essential for repair of the reefs as well as coral recovery due to physical, biological and chemical erosion (Meissner, Lippmann & Gupta, 2012).

The rise in the amount of carbon dioxide is said to be good for seagrass and bad for the corals. The rise in atmospheric carbon dioxide will ultimately result in numerous changes in the oceanic chemistry with acidification being one of those changes. Such acidification is associated with reduced coral growth due to reduced calcification thus leading to a reduction in the diversity of the corals (De’ath, Lough &Fabricius, 2009).

Acidification of the ocean is also associated with increased growth of the seaweeds that then compete for space with the corals. Also the algae Crustose Coralline are negatively affected by a rise in carbon dioxide in their early stages of development. The algae act as the most favoured settling site for the coral’s larvae. The negative effect of carbon dioxide increase reduces the abundance of the algae resulting in less corals settling (De’ath, Lough &Fabricius, 2009)

The life of the corals is at risk due to reduction in coral availability, diversity and complexity as a result of increased oceanic acidity. Since the industrialization era to the current day, oceanic PH has been said to reduce and it is anticipated that the trend will continue in futurethus negatively affecting the corals. In order to have similar corals as those that existed in the past, something has to be done in order to reduce oceanic acidity and save the life of these vital organisms in the ocean

Reference

• Andersson, A. J., & Gledhill, D. (2013). Ocean acidification and coral reefs: effects on breakdown, dissolution, and net ecosystem calcification. Annual Review of Marine Science, 5, 321- 348.
• De’ath, G., Lough, J. M., &Fabricius, K. E. (2009). Declining coral calcification on the Great Barrier Reef. Science, 323(5910), 116-119.
• McClanahan, T. R., &Cinner, J. E. (2008). A framework for adaptive gear and ecosystem‐based management in the artisanal coral reef fishery of Papua New Guinea. Aquatic Conservation: Marine and Freshwater Ecosystems, 18(5), 493-507.
• Meissner, K. J., Lippmann, T., & Gupta, A. S. (2012). Large-scale stress factors affecting coral reefs: open ocean sea surface temperature and surface seawater aragonite saturation over the next 400 years. Coral Reefs, 31(2), 309-319.