Light Pollution Induces Increased Seabird Mortality

By Olivia Schuitema, SRC Intern

Light pollution has increased fiercely over the last century, resulting in mass fatality events in seabirds, one of the most endangered groups of birds (Rodríguez, 2017). This phenomenon, called “grounding,” happens when land-based artificial lights attract seabirds to the shore, causing them to crash into human-built structures such as buildings and fences (Rodríguez, 2017). Once on land, the disoriented birds (Troy, 2013) are vulnerable to predation, starvation, and vehicle collisions, leading to the mass-mortality events.

Figure 1

Composite image of continental U.S. at night, showing light pollution (NASA, 2016).

In reviewing current literature on the topic, data shows that twenty-four of the seabird species most likely to ground due to artificial lights are listed as “globally threatened” on the IUCN Red List (Rodríguez, 2017). A large number of the species affected are petrels and shearwaters (Figure 2). Juvenile individuals flying from the nest for the first time, or “fledglings,” make up 68%-99% of all grounding seabirds (Rodríguez, 2017). Seabird disorientation and the path where fledglings are drawn off course towards land are still uncertain (Troy, 2013), but scientists hypothesize the artificial lights drown out the natural light of the moon and stars.

Figure 2

Newell’s Shearwater, Puffinus newelli (Hawaii.gov).

Three strategies can be taken to prevent the loss of seabird life: avoidance, minimization, and rehabilitation (Rodríguez, 2017). Avoidance (avoiding practices that are known to cause fatalities) can be implemented in both new and current housing developments; new developments can refrain from installing light systems associated with groundings (Rodríguez, 2017), and current communities can remove or turn off lights that are not being used. Minimization reduces the duration and intensity of artificial light on seabird individuals (Rodríguez, 2017), and can be implemented in areas of overlap between humans and seabirds. Rehabilitation is also a method used to rescue grounded birds, where stranding teams and people of the public bring individuals to designated rescue stations. Here, the birds will undergo rehab until they are in “release condition.” However, not all birds survive grounding or rehabilitation efforts, but can be used as indicators of various marine environmental conditions (Rodríguez, 2017). Long-term scientific studies can also utilize seabird carcasses to address issues such as oil pollution (Stienen, 2017).

Figure 3

Seabird Rehabilitation Sanctuary in Ponce Inlet, Florida (Wikimedia Commons).

There is still little information known about seabird attraction to artificial lights. Scientists recommend researching the ecology and biology of vulnerable seabird populations and the effects of light intensity on grounded individuals (Rodríguez, 2017). New classes of lights that are useful for humans, but safe for seabirds can also be explored (Troy, 2013). Overall, seabirds are of great ecological importance and have ecotourism value that support many local economies. As light pollution increases, seabirds are continually at risk of grounding, leading to possible mass-mortality events.

Works Cited

Rodríguez, Airam, Holmes, Nick D., Ryan, Peter G., Wilson, Kerry‐Jayne, Faulquier, Lucie, Murillo, Yovana, . . . Corre, Matthieu Le. (2017). Seabird mortality induced by land‐based artificial lights. Conservation Biology, 31(5), 986-1001.

Stienen, Courtens, Van de Walle, Vanermen, & Verstraete. (2017). Long-term monitoring study of beached seabirds shows that chronic oil pollution in the southern North Sea has almost halted. Marine Pollution Bulletin, 115(1-2), 194-200.

Troy, J., Holmes, N., Veech, J., & Green, M. (2013). Using observed seabird fallout records to infer patterns of attraction to artificial light. Endangered Species Research, 22(3), 225-234.

A right whale pootree: classification trees of faecal hormones identify reproductive states in North Atlantic right whales (Eubalaena glacialis)

By Brenna Bales, SRC Intern

Faecal samples are a surprising wealth of information. One might think that the end product of digestion would not hold more information than simply what an animal has eaten, but in fact, animal excretions can give information about stress levels, sexual maturity, and physiological condition. In this analysis, 112 faecal samples of 81 individually identified North Atlantic right whales (NARW) (Eubalaena glacialis) were assayed for four hormone metabolites: cortisol (stress hormone), oestrogen (female sex hormone), testosterone (male sex hormone), and progesterone (female pregnancy hormone) (Corkeron et. al., 2017). The results were then used to classify each whale in a tree diagram, in one of the following categories: mature male (MM), immature male (IM), immature female (IF), pregnant female (Preg), lactating female (Lact), and resting female (mature, non-pregnant, non-lactating) (Rest) (Figure 1).

Figure 1

The constructed tree of known reproductive states of North Atlantic right whales (Eubalaena glacialis) (Corkeron et. al., 2017).

In order to confirm results, the hormonal identifications were compared with previously collected life-history data from the NARW Identification Database (Right Whale Consortium, 2012). The surveying efforts of these whales off the Eastern coast of North America extends back to 1986, with 80% of the population sighted each year (Hamilton et. al., 2007). This is key to confirming the results of a 13-year data set, and supplements the claims that NARWs are an ideal species for faecal analysis, due to the wealth of identification data. Furthermore, the consistent diet of the whales, minimal temperature variation in the study area, and the rapid collection of samples make this faecal hormone analysis possible.

Figure 2

A North Atlantic right whale and calf swim side by side. (source: http://www.noaanews.noaa.gov/stories2009/ images/whale_andcalf.jpg).

Cortisol hormone concentrations can also be used to identify stress levels in NARWs from anthropogenic impacts, similar to what has been done in killer whale (Orcinus orca) populations, relating boat traffic to stress (Ayres et. al., 2012). As environmental stressors continue to mount, wild, free-ranging marine animal populations are at risk. The confirmation of anthropogenic impact is essential, so appropriate conservation actions can be taken. In conclusion, this classification of sexual maturity is useful in estimating the proportion of breeding individuals in the NARW population, and hopefully can be used in future studies to assess the health and reproductive abilities of the population.

References
Ayres KL, Booth RK, Hempelmann JA, Koski KL, Emmons CK, Baird RW, Balcomb-Bartok K, Hanson MB, Ford MJ, Wasser SK (2012) Distinguishing the impacts of inadequate prey and vessel traffic on an endangered killer whale (Orcinus orca) population. PLoS One 7: e36842.

Hamilton PK, Knowlton AR, Marx MK (2007) Right whales tell their own stories: the photo-identification catalog. In SD Kraus, RM Rolland, eds, The Urban Whale: North Atlantic Right Whales at the Crossroads. Harvard University Press, Cambridge, MA, pp 75-104.

Right Whale Consortium (2012). North Atlantic Right Whale Consortium Identification and Sightings Databases 31 December 2012 (New England Aquarium, Boston, MA, USA).

The Importance of Deep-Water Coral on the Antarctic Continental Shelf

By Sianna Raquel Vacca, SRC Intern

Throughout history, both natural and man-made causes have resulted in long-lasting effects on the oceans. While most organic processes yield gradual change, the impact of human activity alters nature by prompting and accelerating otherwise irregular events (e.g. rapid ocean acidification, warming, habitat destruction), diminishing the oceans’ supply of pristine areas and ecosystems. A “pristine ecosystem” is defined as an area that has been either minimally affected or entirely untouched by human activity/influence. The depletion of these pristine areas impedes upon the ability to observe marine environments in their natural, undisturbed states. However, not all pristine marine habitats have been affected just yet.

Figure 1

Antarctic seafloor depicting an array of marine organisms including Antarctic scallops and brittle stars. Pixabay.

A study conducted by a group of scientists based in Barcelona, Spain recently explored the pristine populations of deep-water corals on the Antarctic continental shelf. Thanks to geographical factors, the practically desolate waters of the Antarctic have provided protection to these gorgonian species from human influence and this study, as one of the first of its’ kind, has contributed to filling several gaps regarding the population characteristics of this species. While little was known about their distribution, abundance, and demographics, ROVs (remotely operated vehicles) have proven that gorgonians play an important role in the creating the geographical structure of many Antarctic continental shelfs by adding a three-dimensional aspect to their habitat. The purpose of this study was to learn about and understand the ecological role of these corals, which can be used in conservation efforts.

The results showed that coral populations in Antarctic benthic environments were not only booming, but that their distribution gradually differed between the Northern and Southern regions of the Weddell Sea. They thrive at depths of 250-350m and despite such extreme conditions, gorgonian density is similar to coral population values in temperate and tropical ocean floors. This discredits the widely accepted belief that species richness proportionately decreases with increasing latitude. Hydrodynamic conditions are also favorable for gorgonians at these depths by accumulating particle suspension in the near-bottom water layers. These strong currents are advantageous by providing a constant food supply and keeping reefs clear of sediment.

While gorgonian populations proved to be overwhelmingly healthy in the Antarctic, they are exposed to certain environmental threats that a tropical reef would never face. Due to their slow growth rate and reproduction type, gorgonians are especially vulnerable to iceberg scouring. Iceberg scouring events occur when icebergs drift into shallow areas and come into contact with/scrape the seafloor as it moves along. Additionally, anthropogenic activities such as bottom-trawling and by-catch fishing result in large habitat destruction for these species. The authors of this study hope to bring awareness to the abundance and health of gorgonians, which can at least begin to protect them from human-related threats.

Figure 2

A diagram portraying iceberg scouring, the process by which icebergs scrape the seafloor as it drifts through the ocean. Iceberg scouring events pose a threat to gorgonian species on the Antarctic continental shelf because of their slow growth rate, reproduction type, and inability to quickly recover. Flickr.

References

Ambroso, Stefano, et al. “Pristine Populations of Habitat-Forming Gorgonian Species on the Antarctic Continental Shelf.” Scientific Reports, vol. 7, no. 1, 25 Sept. 2017, doi:10.1038/s41598-017-12427-y.

The effects of elevated temperature and ocean acidification on the metabolic pathways of notothenioid fish

By Abby Tinari, SRC intern

Notothenioid fish are typically found in the deep, cold waters of the Southern Ocean. Three species of fish native to the Ross Sea were studied to see how they may react to warmer and more acidic oceans.

Figure 1

(a) Pagothenia borchgrevunki (http://adam.antarcticanz.govt.nz), (b) Trematomus newnesi (http://adam.antarcticanz.govt.nz), (c) Trematomus bernacchii (Wikimedia Commons), (d) Ross Sea Location (Wikimedia Commons)

Methods

To measure the effects of temperature on the fish, individuals were randomly selected and placed in one of the four experimental treatment tanks. The experimental tanks consisted of a control treatment, a low temperature and high pCO2, high temperature and low pCO2, and high temperature and high pCO2 to test the individual and overall effects of temperature and pCO2 on the three-fish species. pCO2 is the partial pressure of carbon dioxide in the water. Each fish had an acclimation period that lasted anywhere from 7 to 56 days. Measurements of fish condition and growth were recorded over the course of the experiment. A few tests were performed to analyze enzymatic changes in the liver, white muscle tissue, and gills. One of the tests, the citrate synthase activity test measured how well the fish can release stored energy.

Results

T. bernacchii, the emerald codfish, was the only fish to display any significant impact from the treatments. The growth and condition declined significantly due to temperature but slowed as the acclimation period increased. The group of fish with the faster acclimation period had the largest decline of condition and growth, especially those that also had the multi-stress (high temperature and high <em>p</em>CO2) treatment. The temperature also influenced the Emerald Codfish’s oxygen consumption and metabolic rate. The high <em>p</em>CO2 tank had a small increase in metabolic rate. There were significant increases in citrate synthase activity, the first of which occurred after 7 days in the multi-stress treatment in the gills. By the 28-day acclimation, all treatments had significantly increased in both the liver and the gills.

The bald notothen, P. borchgrevinki, metabolic rates were significantly affected by temperature in the shorter acclimation periods. Interestingly, the oxygen consumption rates decreased in the high temperature treatments over time. Time and temperature were the main drivers in the citrate synthase activity increase in the gill tissues.

Metabolic rates in T. newnesi differed significantly between the acclimation groups with temperature as the main effect. No significant difference between pCO2 and temperature was present. There was however, an increased oxygen consumption rate after the 7 and 28-day acclimation period. The T. newnesi showed the least sensitivity to the treatments. The changes in Citrate synthase activity were not statistically significant.

Figure 2

Citrate synthase enzyme activity (±SE) of Trematomus bernacchii gill (A) and liver tissues (B), Pagothenia borchgrevinki gill (C) and liver tissues (D) and Trematomus newnesi gill (E) and liver tissues (F) acclimated at 7, 28 and 42 or 56 days to a control treatment (low temperature + low pCO2; black bars), low temperature + high pCO2 (white bars), high temperature + low pCO2 (dark gray bars) and high temperature + high pCO2 (light gray bars with cross hatches). Groups not connected by the same letter are significantly different from each other. (Enzor et al. 2017)

Discussion

This group of fish, the Notothenioid fish are critical to the Ross Sea food web. The three-species studied are consumed by seals, penguins, and other top predators. Studies like this one help to predict population responses for not only the Notothenioidei suborder but also other species which depend on these individuals for food.

Temperature had a greater adverse effect on the energy demands for two of the studied species. The fish may be able to acclimate to the higher temperatures, but only to an extent. Higher temperatures may mean a decreased ability to efficiently ingest food leading to decreased growth and other detrimental effects as seen in the Emerald codfish.

It should be noted that the long-term implications of the temperature and pCO2 on growth should be cautiously interpreted due to the small sample size and lack of growth even in the control samples.

References

Enzor LA, Hunter EM, Place SP (2017) The effects of elevated temperature and ocean acidification on the metabolic pathways of notothenioid fish. Conserv Physiol 5(1): cox019; oi:10.1093/conphys/cox019

Dispersants: A Modern Method For Cleaning Up Oil Spills: Advantages and Disadvantages

By Nicole Suren, SRC intern

In 2010, the Deepwater Horizon oil rig in the depths of the Gulf of Mexico exploded, causing the release of approximately 500 thousand tons of crude oil into the ocean in the second largest oil spill in global history, commonly known as the BP oil spill (Fingas, 2013). This spurred constant media coverage of the spill itself, as well as the cleanup. Oil spill cleanup generally includes several main steps: first the spill is contained using booms, then oil is absorbed on a large scale and skimmed off the ocean surface using boats and large amounts of absorbent materials (often more booms), and finally materials called sorbents are added to the water to remove trace amounts of oil not visible to the naked eye. What was unique about the cleanup of the Deepwater Horizon spill was the incredibly high amount of compounds called dispersants used before and during the official cleanup. Dispersion is when fine droplets of oil are transferred into the water column by wave action or turbulence (Fingas, 2013), removing oil from large slicks at the surface and allowing it to diffuse into deeper parts of the ocean. Dispersants are compounds usually sprayed on oil slicks that promote the formation of small droplets of oil, making dispersion much easier when waves stir up the oil. BP’s heavy use of dispersants was very controversial because dispersants had never been used on such a large scale before. Scientists were uncertain about two main things: 1) the effectiveness of dispersion as a cleanup method, and 2) the potential toxicity of dispersants on their own and/or mixed with oil. Since 2010, a significant amount of progress has been made in determining the effectiveness and toxicity of dispersants.

An airplane spraying dispersants over an oil slick in the Gulf of Mexico (Source: Wikimedia Commons)

An airplane spraying dispersants over an oil slick in the Gulf of Mexico (Source: Wikimedia Commons)

The petroleum industry is confident that dispersants are helpful in cleaning up oil spills (Schrope, 2013). Independent scientists, however, have not found data on the subject to be quite as conclusive. The effectiveness of dispersants depends on a variety of factors, including the type of oil, wave energy, and the amount of dispersant added. Dispersants are never 100% effective, meaning they never cause 100% of the oil from an oil slick to disperse, and even after the initial dispersal has occurred oil can often resurface within a day or so to reform the slick (Fingas, 2013). A study funded by Exxon Mobil describes a very optimistic outlook on the effectiveness of dispersants, saying that oil degrades faster when dispersed than when on shore (degradation by bacteria can occur within a matter of weeks when dispersed, according to the study) and that despite the fact that the dispersants have been shown to remove close to 50% of the oil from an oil slick in EPA-approved lab tests, they remove closer to 95% of oil in large wave tank experiments, leading Exxon’s scientists to believe that EPA estimations of effectiveness greatly underestimate effectiveness in the field (Prince, 2015). Biodegradation is a term that describes the degradation of a material by bacteria, and it is an important concept in relation to the effectiveness of dispersants. Petroleum companies argue that the increased surface area of the oil provided by dispersants allows bacteria greater access to the oil, and therefore biodegradation can occur more quickly (Prince, 2015). However, this assessment does not take into account other materials like tar that are not so easily degraded by bacteria or dispersed. Furthermore, each species of bacteria that can use oil as a food source “can utilize only a few related compounds at most, [so] broad-spectrum degradation does not occur.” (Fingas, 2013) Since degradation is not complete, dispersed oil can then be sequestered at the bottom of the ocean in association with marine snow (organic materials that rain down to the deepest parts of the ocean from the surface). In the presence of dispersants, the amount of marine snow increases dramatically and includes droplets of oil, creating an oily sludge along the ocean floor that is not being degraded by bacteria (Justine S. van Eeenennaam, 2016).

An oil slick untreated by dispersants being cleaned up by skimmer boats. The oil appears very dark and dense from the surface. (Source: Wikimedia Commons)

An oil slick untreated by dispersants being cleaned up by skimmer boats. The oil appears very dark and dense from the surface. (Source: Wikimedia Commons)

An oil slick treated by dispersants. The color of the oil slick appears much lighter from the surface, as a lighter or coffee-colored oil slick is typical of the appearance of dispersed oil. Shown here May 6, 2010, is an aerial view of the Deepwater Horizon oil spill off the coast of Mobile, Ala., taken from a U.S. Coast Guard HC-144 Ocean Sentry aircraft. (U.S. Navy photo by Mass Communication Specialist 1st Class Michael B. Watkins/Released)

An oil slick treated by dispersants. The color of the oil slick appears much lighter from the surface, as a lighter or coffee-colored oil slick is typical of the appearance of dispersed oil. May 6, 2010, is an aerial view of the Deepwater Horizon oil spill off the coast of Mobile, Ala., taken from a U.S. Coast Guard HC-144 Ocean Sentry aircraft. (U.S. Navy photo by Mass Communication Specialist 1st Class Michael B. Watkins/Released)

Not only is this sludge problematic because it is stopping the biodegradation of the oil touted by Exxon’s study, but it is toxic to the organisms that become buried below it (Justine S. van Eeenennaam, 2016). Toxicity of dispersants is a major concern, and several studies have shown that dispersants can compound a toxic situation created by the initial oil spill. First, increased biodegradation is promoted as an ideal solution for oil cleanup facilitated by dispersants, but “the aquatic toxicity of the biodegradation products is sometimes greater than that of the parent compounds,” (Fingas, 2013) so while the dispersants themselves are less toxic than oils by a magnitude of ten (Fingas, 2013), (Prince, 2015), they facilitate the production of more toxic compounds. The Exxon study also claims that dispersants show neither androgen nor estrogen receptor activity (Prince, 2015), meaning that they do not have any effect on regular endocrine function of organisms that consume or come in contact with them. While this is true for the dispersants used in the Deepwater Horizon spill, it is certainly not true for all dispersants (Richard S. Judson, 2010). Many dispersants have also been shown to be lethal to cells in culture, suggesting that they are toxic to larger animals as well (Richard S. Judson, 2010), and they can persist in the water column for years, rather than break down quickly as predicted (Helen K. White, 2014). In short, dispersants are not innocuous tools for cleanup, but have significant environmental effects that cannot be ignored.

The main benefit of dispersants is that their use can prevent large slicks of oil from contaminating coastal ecosystems and adversely affecting sensitive species like sea birds. However, “the use of dispersants remains a trade-off between toxicity to aquatic life and saving birds and shoreline species.” (Fingas, 2013) No matter what, introducing oil to an ecosystem will adversely affect that ecosystem. Because biodegradation is a questionably effective method of oil removal from marine ecosystems, the use of dispersants is essentially humans choosing which ecosystems should be more or less adversely affected, and since we see and interact with coastal ecosystems far more than deep ocean systems it is no surprise that dispersants are used to protect coastlines. However, the ecological impact of degrading deep water ecosystems should not be underestimated, and the effect of dispersants should be monitored long-term to determine whether they should be used again.

Works cited

Fingas, M. (2013). The Basics of Oil Spill Cleanup (3 ed.): CRC Press.

Helen K. White, S. L. L., Sarah J. Harrison, David M. Findley, Yina Liu, Elizabeth B. Kujawinski. (2014). Long-Term Persistance of Dispersants following the Deepwater Horizon Oil Spill. Environmental Science and Technology Letters, 1(7), 295-299.

Justine S. van Eeenennaam, Y. W., Katja C.F. Grolle, Edwin M. Foekema, AlberTinka J. Murk. (2016). Oil spill dispersants induce formation of marine snow by phytoplankton-associated bacteria. Elsevier, 104, 294-302.

Prince, R. C. (2015). Oil Spill Dispersants: Boon or Bane? Environmental Science and Technology, 49(11), 6376-6384.

Richard S. Judson, M. T. M., David M. Reif, Keith A. Houck, Thomas B. Knudsen, Daniel M. Rotroff, Menghand Xia, Srilatha Sakamuru, Ruili Huang, Paul Shinn, Christopher P. Austin, Robert J. Kavlock, David J. Dix. (2010). Analysis of Eight Oil Spill Dispersants Using Rapid, In Vitro Tests for Endocrine and Other Biological Activity. Environmental Science and Technology, 44(15), 5979-5985.

Schrope, M. (2013). Researchers debate oil-spill remedy: oil industry maintains that dispersants should be part of routine response to deep-water blowouts. Nature, 461.

How the geographic range characteristics of a species can affect its conservation

By Elana Rusnak, SRC intern

For many of us scientists, our end goal is conservation of our target species. But what does this mean, and how do we reach these goals? Unfortunately, the answer to this question is not cookie-cutter and requires the input of multiple factors that are not so easily or frequently studied.

At the largest scale, the two broad measurements of geographic range can either provide too much or too little area to be taken into account with regards to protecting a certain species: the extent of occurrence (EOO) and the area of occupancy (AOO). The area of occupancy is all the local area in which a species has been recorded, but only accounts for those localized areas. It may not take into consideration the other hospitable habitat in which individuals simply haven’t been recorded yet. The extent of occurrence is generally larger; as it encompasses all of the area a species could possibly live in, including the space between the recorded individuals (Gaston, 1991). The debate between area of occupancy and extent of occurrence may yield different results, which could cause complications especially with policymakers. While it may seem ideal to cover as much habitat as possible in order to protect a species, it is expensive and requires a lot of enforcement, therefore making it difficult for policymakers to go only on extent of occurrence, since it might include habitat in which the species does not ever reside. However, it also might include area in which a species is migrating, but only during a small part of the year. Why would they want to spend valuable resources to protect an area that does not need to be protected? For example, the White Ibis has year-round populations along the coast of the southern United States and Mexico, as well as a population in northern South America. They are migratory birds, and spend part of the year more inland in the United States, yet it is only a few months of the year (The Cornell Lab of Ornithology, n.d.). If these birds were to become endangered, it is likely that there would be conflicts in determining how much of the yearly range should be protected and why.

The area of occupancy of the White Ibis (Eudocimus albus) (http://geocat.kew.org/editor)

The area of occupancy of the White Ibis (Eudocimus albus) (http://geocat.kew.org/editor)

The extent of occurrence of the White Ibis (Endocimus albus) (http://geocat.kew.org/editor)

The extent of occurrence of the White Ibis (Endocimus albus) (http://geocat.kew.org/editor)

Another factor determining the geographic range is it’s shape. The shape of the geographic range generally constrained from the North and South, or from the East and West. North-South constraints are frequently controlled by the macroclimate (ex. temperature and precipitation), whereas East-West constraints are controlled by topography and availability of suitable habitat (Brown et al., 1996).

Habitat controlled by macroclimate, creating North-South constraints

Habitat controlled by macroclimate, creating North-South constraints

Habitat controlled by topography, creating East-West constraints

Habitat controlled by topography, creating East-West constraints

A problem in present times stems from climate change, which may alter the range shape due to rising temperatures. If a northern bird’s climate suddenly becomes too warm to endure, they may move north in order to compensate. If they were protected in their original habitat, however, the protected area may not cover their new habitat, which may result in population losses. A study done by Møller et al. in 2002 indicates just that: rapid climate changes are associated with dramatic population loss of migratory birds in the Northern Hemisphere. This can be a difficult situation for policymakers, especially if the population is both moving and declining at rapid rates.

Brown et al. further describes the issues of range size and boundary by commenting on the fact that the range edge is never defined. The internal populations of a geographic range tend to be steadier, with larger, constant populations. However, the outer edges of the range are mercurial, which makes it very difficult to determine. This brings us back to the extent of occurrence vs. area of occupancy issue. While individuals are seen at the borders of ranges, or in an excluded area, it does not necessarily mean that they are within the “geographic range” of their species. Since the edges change constantly, policymakers generally need to decide if they want to protect the bulk of the population, or the entire area that they cover.

At the smallest of scales, genetics also plays a role in conservation. While species can change and evolve into different species over very long periods of time, the genetic analysis tools we have today can show that what we thought was one species is actually two. For example, the California newt (Taricha torosa) was divided into two species in 2007. The newts living on the coast keep their Latin name, while the separate species living in the sierra has been named Taricha sierrae. (Kutcha, 2007). Modern speciation events like this can also have an effect on policy. If both species are endangered, policymakers would need to protect both species instead of just the one beforehand, which leads to more money spent and another proposal to be passed.

It is no wonder, now, that policymakers take so long to get a species protected. The factors discussed above are only a few of the considerations they must take into account in order to pass a proposal supporting protecting part of, or the entire geographic range of a species. With all that being said, every bit of science contributing to conservation is important science, which is why we do it.

Literature cited

Brown, J. H., Stevens, G. C., & Kaufman, D. M. (1996). The geographic range: size, shape, boundaries, and internal structure. Annual review of ecology and systematics, 27(1), 597-623.
Gaston, K. J. (1991). How large is a species’ geographic range?. Oikos, 434-438.
Møller, A. P., Rubolini, D., & Lehikoinen, E. (2008). Populations of migratory bird species that did not show a phenological response to climate change are declining. Proceedings of the National Academy of Sciences, 105(42), 16195-16200.
Shawn R. Kuchta (2007). “Contact zones and species limits: hybridization between lineages of the California Newt, Taricha torosa, in the southern Sierra Nevada”. Herpetologica. The Herpetologists’ League. 63 (3): 332–350. doi:10.1655/0018-0831(2007)63[332:CZASLH]2.0.CO;2.
The Cornell Lab of Ornithology. (n.d.). White Ibis. Retrieved March 25, 2017, from https://www.allaboutbirds.org/guide/White_Ibis/id