Seascape ecology and coral reefs. Seascape ecology is a relatively new study in the field of landscape ecology. Landscape ecology

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1 Michelle Dennis NRS 534 Term Paper Seascape ecology and coral reefs Seascape ecology is a relatively new study in the field of landscape ecology. Landscape ecology was developed over a half a century ago primarily for managing terrestrial environments. It focuses on the causes, changes, and ecological functions associated with spatial patterns (Pittman et al. 2011). Seascape ecology, or the study of wholly or partially submerged marine landscapes and marine species, uses the studies from landscape ecology for an approach. Seascape ecology was developed to understand and manage marine environments and is an important study for the future. As I stated before seascape ecology is a relatively new study, most of the papers that were found were from 2010 and later with only two paper from the 1990s. I focused my topic on how coral reefs are effected by fragmentation and degradation, as well as, the effects of climate change on reefs and reef fish. Global climate change is rapidly changing the earth we live in and will have long term impacts on the worlds ecosystems. Exactly how much each ecosystem will be impacted through their service and function is difficult to predict (Adam et al. 2014). Due to climate change, coral reefs will face many threats including, ocean acidification caused by CO2 emissions, sea level rise due to thermal expansion and melting of polar icecaps, and potentially increased frequency of severe storms resulting from rising atmospheric temperatures (Adam et al. 2014). It is really important to look at how each threat will effect the coral reefs and reef fish in the future so we can manage them effectively. Most of the papers I reviewed looked at different situations of how to induced the effects of climate change on coral reefs and how the reefs were effected, as well as, the coral reef fish. One of the most interesting papers I found was by Adam et al. (2014). This paper looked at how coral reef fish communities will respond to disturbances. In the article, they looked at two events, the outbreak of COTS (corallivorous crown of thorn sea stars) and a tropical cyclone. The paper also looked at the short and long term effects on coral reefs and reef fish. I thought it was very interesting that the sea stars can

2 completely degrade the coral reefs so there is only the dead calcium carbonate skeleton left or the physical structure. This is a great representation of how increase CO2 levels effect coral reefs by bleaching them. Bleaching also leaves the physical structure intact but the skeleton is left dead. A coral reef that has been decimated by a tropical cyclone is also reviewed because tropical storms will increase in intensity and frequency in the future due to global climate change. The methods for this paper I also though were intriguing because they used live wild corals that have already been affected either by COTS or a tropical cyclone and then looked at how the reef and fish were effected for the next few years. Adam et al. (2014) found in their results that the tropical cyclone had a larger impact on the coral reef fish they the degradation of the corals by COTS. They actually found that even though the skeletons were being degraded the coral reef ecosystem lasted a lot longer then was originally thought. This is very telling because it means the coral reefs will be able to survive a longer amount of time with the effects of ocean acidification from climate change due to the physical structure of the reef being still intact. They also found that when a coral reef is hit by a tropical cyclone the short term effects are a lot greater then the long term effects. In the short term, most of the reef will not survive and the reef fish will leave that particular area. But in the long term, the coral reefs are more likely to survive because they are still connected to other reefs which provide larval for corals, as well as, reef fish. Bonnie et al. (2011) looked at how coral reef fish are effected by coral reef fragmentation and degradation. Bonnie et al. (2011) induced fragmentation to a reef and observed how long it took for the reef fish to abandon the habitat. The result of the study concluded that when 75% of the coral reef was lost then the reef fish abandoned the reef and moved on. Caley et al. (2001) also looked at fragmentation with coral reefs and found that there are neutral or positive effects of fragmentation if the reef habitat is not being degraded. This also proves the point that coral reefs will be able to survive in the long term even with the effects of global climate change.

3 Another study looked at the connectivity between mangroves and coral reefs (Mumby 2006). I thought this was study was interesting because it brought landscape ecology concepts into marine environments. Mumby (2006) looked at how juvenile reef fish use mangroves near by coral reefs as a nursery habitat and then move back to coral reefs habitats as adults. It is definitely important to do more research on these corridors that connect the mangroves to the coral reefs. Not only do the coral reefs and mangroves need to be managed in the future but corridors do as well because if the corridor is cut off and poorly managed the nursery habitat is lost to the reef fish. In conclusion, seascape ecology is still a work in progress and needs to be studied more in the future. Coral reefs through these studies may actually be able to survive and adapt to global climate change but still need to be managed so further damage is not done. Marine environments will be highly effected by global climate change in the future and needs to be studied more so we can efficiently manage the areas that are most important. Annotated Bibliography: Acosta, Charles A., and Denice N. Robertson. "Diversity in coral reef fish communities: the effects of habitat patchiness revisited." Marine Ecology Progress Series 227 (2002): This article revisited the effects of patch size on diversity and structure of coral reef fish communities in Glover s Reef. It also looked at the the number of reef patches, fish species richness, species evenness, and species density on large and small reefs, as well as, the spatial distribution of species. Some results from the study were larger reefs had generally more reef fish species then smaller reefs except for one large reef had less species than two of the smaller reefs. I thought it was very interesting that even though the larger reefs had more fish, the species evenness was almost the same on large reefs compared to smaller reefs. Also, the number of rare species was significantly higher on smaller reefs which is intriguing. Even when they eliminated predators and rare small reef dwellers, the smaller reefs still had a higher amount of rare species. Isolated reefs also had a high amount of species that only used that particular reef due to spatial distribution. More research needs to be done on habitat patchiness on coral reef fishes. Adam, Thomas C., et al. "How will coral reef fish communities respond to climate driven disturbances? Insight from landscape scale perturbations." Oecologia (2014): Global climate change is rapidly changing disturbance regimes in coral reefs, which are an important factor in marine ecosystems. It is important to learn more about coral reefs with the effects of climate change because reefs are a critical habitat for many other species. In this article, they looked at coral reefs in the Pacific island of Moorea, French Polynesia to see the impacts of coral mortality and how it affected the habitat of coral reef fish. In the article they looked at two events, a COTS

4 (corallivorous crown of thorn sea stars) outbreak which killed coral tissue but left the skeleton intact and a tropical cyclone which removed the corals entirely to see how it affected reef fish assemblages. The article concluded that the tropical cyclone had a larger impact on the coral reef fish then the degradation of the coral reef skeletons. This is interesting because the coral reef habitats will be able to survive a lot longer with the effects of climate change. Unfortunately, when the fish abandon the coral reefs, the chances of the coral reefs surviving is very slim. This is due to the reef fish supporting recruitment, growth, and survivorship or corals. This creates a feedback loop that will affect the recovery of the coral reefs in the future. Coral reefs affected by tropical cyclones are more likely to survive because they are still connected to other reefs which provide larval corals and fish. Bonin, Mary C., Glenn R. Almany, and Geoffrey P. Jones. "Contrasting effects of habitat loss and fragmentation on coral associated reef fishes." Ecology 92.7 (2011): This article looked at how disturbances affect coral reefs through habitat loss and fragmentation and how it affects the distribution of coral reef fishes over time. It is important to figure out how the coral reef fish are affected to work out how to manage them in the future. In this study they looked at survival, abundance, and species richness of recruits in both situations and the effects of the two situations, as well as, if the amount of habitat available during fragmentation have different effects. I thought it was interesting how they set up the experiment and how they were able to completely separate each situation. The results included that after 16 weeks are 75% live coral habitat loss, the abundance of reef fish was at the lowest. Also, when 75% of coral reef was lost, fragmentation actually helped the survival which is unexpected. Fragmentation after 6 weeks into the study, had a 3 times greater abundance and richness of reef fish than the control reefs and although it declined after 6 weeks it was still higher then the control. Over time habitat loss increased in negative effects on the abundance and richness of reef fishes. This study is important because it shows that since habitat loss and fragmentation will often happen together, positive fragmentation effects may actually be a buffer against the negative effects of habitat loss. Ault, Timothy R., and Craig R. Johnson. "Spatial variation in fish species richness on coral reefs: habitat fragmentation and stochastic structuring processes." Oikos (1998): This study looks at species richness on fragmented reef habitats and the mechanisms underlying spatial variation in species richness with two reefs in the southern part of the Great Barrier Reef. The spatial variation was looked at on a patchy and contiguous reef and the species richness was looked at on a random placement model and a group placement model. An interesting result is the species to area relationship (higher rate of encountering new species) was significantly higher in patch reef sites than for contiguous reef sites. This could have been due to the edge effect and how patch reef sites are bordered by sand therefore a different habitat for the species while continuous reefs only have one habitat. Therefore, patchy reefs are more heterogenous and will attract more species. Pittman, S., et al. "Seascape ecology: application of landscape ecology to the marine environment." Mar Ecol Prog Ser 427 (2011): This article looks at the approach to landscape ecology in coastal and shallow marine environments, as well as, gaps in knowledge and potential directions for future advancements of seascape ecology. Seascape ecology is a new and emerging field with a basis from landscape ecology which looks at the causes and changes of ecological functions associated with spatial patterns. Due to remote sensing through GIS, complex habitats such as coastal zones, coral reefs, mangroves can be looked at in fine detail which helps while doing seascape ecology studies. It is interesting how new the study of seascape ecology is and how much future research needs to be done to fully understand the study area.

5 Mumby, Peter J. "Connectivity of reef fish between mangroves and coral reefs: algorithms for the design of marine reserves at seascape scales." Biological conservation (2006): This article looks at algorithms of the importance to juveniles, the connectivity, and areas of nursery habitat that mangroves have on coral reefs. Many reef fish will move from coral reefs to mangroves within their lifecycle due to limiting food, predation, and the need to reproduce in areas with greater dispersal survival. It is important to research more about the movement of these organisms so we can manage and protect the corridors between habitats. The first algorithm depended on the size of the nursery habitats to make an assumption and that reef fish move directly from nursery habitats to coral reefs. Therefore, the closest coral reefs will have the most abundance. The second algorithm looked at connectivity between mangroves and coral reefs. It is interesting because the more overall connectivity the more likely they are to have higher rates of immigration. The third, looks at mangrove critical connectivity (MCC). This is when there is a few amount of coral reefs connected to a large area of nursery habitat in a mangrove. The result was the higher MCC the higher the amount of reef fish using that connectivity. It is interesting because these corridors should be managed the most in the future. Hattori, Akihisa, and Miyako Kobayashi. "Configuration of small patch reefs and population abundance of a resident reef fish in a complex coral reef landscape." Ecological research 22.4 (2007): This article looks at the structure of the coral reef habitat to assess the order of protection for each and how to manage them. Coral reefs have a enhanced species diversity and population abundance when the reef is heterogenous and patchy. One of the main points in the article was to look at the relationship between the patch reef configuration and the population abundance of a resident fish in a complex coral reef landscape. This study took place in Japan in 2001 and 2002 and the resident fish it looked at was the anemone fish Amphiprion frenatus and its anemone Entacmaea quadricolor. To observe these habitats, aerial photographs were taken, as well as scuba diving. The article found that the number of host resident fish was highly correlated to the size of the reef assemblage. The size of the host assemblage or the number of hosts can be used as an indicator of anemone fish abundance which I though was very interesting. Another interesting component the article found was the total area and total perimeter were important factors in how the habitat quality was due to higher host abundance. Grober Dunsmore, Rikki, et al. "Influence of landscape structure on reef fish assemblages." Landscape Ecology 23.1 (2008): In this article, they looked at the relationship between landscape structure and reef fish assemblage structure in the US Virgin Islands. One interesting aspect of the study is that it found out that most of the variation in abundance of fishes was due to reef perimeter to area ratio and the number of habitat patches. Another interesting point to consider was the fat that no reef fish assemblage parameter was correlated with reef size. Habitat diversity of coral reefs was also not a good indicator of reef fish diversity and abundance which is different from terrestrial research in landscape ecology. For research in the future one could look at the specific habitat types instead of habitat diversity. Other interesting findings are the positive association of reef perimeter to area ratio with the abundances of transient fishes such as jacks which may reflect a foraging behavior on reef edges. Also, surrounding matrix or context of individual reef patches has a strong influence on the assemblage structure of reef fishes which is important for future management and design. When making management plans, it should consider how well a patch is connected to other in the landscape. Another interesting fact is that the same landscape can be perceived differently by different species.

6 Grober Dunsmore, R., et al. "Reef fish and habitat relationships in a Caribbean seascape: the importance of reef context." Coral Reefs 26.1 (2007): This article looks at how coral reefs are connected through habitat patches by fish movements. The connection between habitats are important to manage because it increases the health and integrity of ecosystems. Without proper management of these corridors, it will likely result in changes in the community structure and loss of key species. Predictions that were tested in the article were the total reef fish abundance and total species richness as well as abundances of grunts, snappers, groupers, mobile invertebrate feeders, and guild of sea grass associated taxa would be greater at reefs with greater amounts of sea grass in close proximity, abundances of resident reef fishes would not be influenced by reef context, and reef fish assemblage structure would be different at reefs without sea grass nearby. I thought it was interesting that their prediction was correct for how the abundances and species richness was higher at reefs with a greater coverage of sea grasses. I also thought it was interesting that juvenile reef fish will use the sea grasses as a nursery. Julian Caley, M., Kathryn A. Buckley, and Geoffrey P. Jones. "Separating ecological effects of habitat fragmentation, degradation, and loss on coral commensals." Ecology (2001): This article looks at the need to conserve species in habitats that are increasingly fragmented. They first did a survey to look at species richness and total abundance as well as species abundance within the coral colonies. They studied two species from the coral reefs a crab and shrimp. After they did the survey, they manipulated the reef and investigated the responses to habitat fragmentation and degradation. Their results concluded that habitat degradation had a much larger impact on the reef then fragmentation did. I thought it was interesting that habitat fragmentation on coral reefs with the absence of loss and degradation had either neutral or positive effects. Also, species richness was most likely directly associated with habitat volume. As the reef was degraded, species richness and abundances decreased. This is important for future management strategies. Ault, Timothy R., and Craig R. Johnson. "SPATIALLY AND TEMPORALLY PREDICTABLE FISHCOMMUNITIES ON CORAL REEFS." Ecological Monographs 68.1 (1998): This article aimed to answer three main questions, is there any evidence that fish communities vary through time in a predictable direction or fluctuate around a stable configuration, is the overall magnitude of temporal variability of a particular fish assemblage related to the size and connectivity of the survey patch, and is there any evidence that recruitment events are primarily responsible for temporal variation in fish community structure. They found that the fish structure was different on a continuous reef compared to a patchy reef. I thought it was interesting that through all the reef sites temporal variation in the structure of fish communities was higher during periods of peak larval recruitment. Also, continuous reef structures tended to be more predictable due to there not being any corridors between patchy reefs. Another interesting result was for many fish species, there was significant relationships between population density and habitat structure, and the magnitude of the relationship is dependent on patterns of post settlement migration. Moberg, Fredrik, and Carl Folke. "Ecological goods and services of coral reef ecosystems." Ecological Economics 29 (1999): This article reviews the ecological goods and services of coral reef ecosystems as well as how they are generated and sustained by biological communities. Coral reefs are among the most productive and biologically diverse ecosystems. Reefs supply people with seafood, recreational possibilities, coastal protection, and cultural benefits. This article also reviews human impacts and the loss of resilience. Humans impact coral reefs by mining, overfishing and destructive fishing such as dynamite fishing, tourism activities, oil mining, and run off of pollutants from urbanization. As a result of their

7 disturbances, the reef systems show poor recovery when affected by natural disturbances. This unfortunately makes them more susceptible to natural disturbances and may cause cascading impacts to the reef systems which I thought was interesting. The article also reviews the effects of bleaching but unfortunately the article is out of date with the effects of global climate change.