Notes: This project focuses on habitat selection of great white sharks, but includes other sharks as well. We’re looking at the effects of temperature, prey, preferences, predators. First time to create a blog, if it is inconvenient to read, very sorry. Hope you enjoy underwater reading!
White, C. F.; Lyons, K.; Jorgensen, S. J.; O’Sullivan, J.; Winkler, C.; Weng, K. C.; Lowe, C. G., and Patterson, H. M., 2019. Quantifying habitat selection and variability in habitat suitability for juvenile white sharks. PloS One, 14(5), e0214642–e0214642. https://doi.org/10.1371/journal.pone.0214642
This article describes habitat selection by recording juvenile white sharks using satellite traps in Baja California. These juvenile white sharks mostly stay in coastal water. Warm temperate water temperature, shallow water depth and near-shore distance are the selection condition and preference for their habitat. Since preys are easier to catch in a nearshore habitat, it also provides a safe shelter for juvenile white sharks from predators. Also, compared with adult white sharks, juvenile white sharks prefer to stay in warm water. This article is very helpful for me because it gives me insight into the lifestyle and habitat choices of young white sharks. It also gave me a better idea of how the habitat of juvenile white sharks differs from that of adult white sharks. Why do they choose the offshore areas? This is a good line of inquiry for me to study habitat selection of great white sharks, because the article describes the habitat selection conditions for juvenile sharks.
Shaw, R. L. ; Curtis, T. H. ; Metzger, G. ; McCallister, M. P. ; Newton, A.; Fischer, G. C., and Ajemian, M. J., 2021. Three-Dimensional Movements and Habitat Selection of Young White Sharks (Carcharodon carcharias) Across a Temperate Continental Shelf Ecosystem. Frontiers in Marine Science, 8, https://doi.org/10.3389/fmars.2021.643831
The white sharks have a wide range and ability to cross the continental shelf. This article surveyed young-of-the-year and young juvenile white sharks across continental shelf and shark nursery habitat use in the New York Bight. Large great whites are relatively rare in the reserve during the summer and fall, providing a safe area for young sharks. Therefore, young sharks will live in shark nurseries for a long time. Both adult and juvenile white sharks seem to dominate the coastal and continental shelves, and are found in areas of deep water. However, the young will expect to be in the high trophic zone, where prey availability is high. The margins of the continental shelf may provide suitable underground habitats for these predators, with high levels of habitat and biodiversity in the marginal waters of the shelf that young white sharks can take greater food resources that accompany this unique subterranean feature. This article is very helpful for me, because it describes young great whites choosing habitat to use in particular terrain. This helps me understand the range of the great white shark.
Curtis, T. H. ; McCandless, C. T. ; Carlson, J. K. ; Skomal, G. B. ; Kohler, N. E. ; Natanson, L. J. ; Burgess, G. H. ; Hoey, J. J. ; Pratt, Jr.; Harold, L., and Klimley, A. P., 2014. Seasonal distribution and historic trends in abundance of white sharks, Carcharodon carcharias, in the western North Atlantic Ocean. PloS One, 9(6), e99240–e99240. https://doi.org/10.1371/journal.pone.0099240
White shark abundance is an important indicator of shark conservation, which requires understanding the distribution of white sharks. In this article, the authors gathered historical and recent reports of white shark catches and sightings in the northwest Atlantic Ocean. The authors et al. analyzed current white shark populations based on seasonal distribution, relative abundance trends, habitat use, and fisheries interactions. In the analysis of distribution, GIS software is used to draw data to match the ocean topography and depth. And the year is divided into four seasons: winter, spring, summer and autumn to analyze the seasonal changes in distribution. In terms of temperature, visualization is used. The temperature and time of each reported white shark sighting were investigated, and the relative abundance of white sharks was compared. The survey found that great white sharks are mainly found in the continental shelf waters of 200m.The current results suggest that white sharks regularly visit these subtropical waters during the winter, which supports seasonal north-south variations in the distribution of white shark populations in the Northwest Pacific. The estimated annual north-south variation in the great white shark population seems to be driven by a combination of environmental preferences and prey availability. Because when sea temperatures exceed 14°C, great white sharks move into summer feeding areas in the northeastern United States. As temperatures drop in the fall, shark populations move south. The authors summed up these overall cruise trends, the abundance of great whites is now on the rise. The help of this article is that it can analyze the habitat selection of sharks under seasonal changes by simulating the seafloor framework with GIS technology. It also gives me a better understanding of the seasonal distribution patterns of great white sharks, and their movement patterns.
Towner, A.V. ; Leos-Barajas, V. ; Langrock, R. ; Schick, R. S. ; Smale, M. J. ; Kaschke, T.; Jewell, O. J. D. ; Papastamatiou, Y. P., and Hopkins, W., 2016. Sex-specific and individual preferences for hunting strategies in white sharks. Functional Ecology, 30(8), 1397–1407. https://doi.org/10.1111/1365-2435.12613
This article examines the hunting strategies of great white sharks and their behavioral patterns towards prey, including gender and personal preferences. The authors used mixed hidden Markov models to acoustic tracking data applied to coastal aggregations of white sharks. That was used to measure two motion states: area-restricted searching (ARS) and patrolling. They tracked white sharks in Gansbaai of South Africa and investigated Dyer Island and Geyser Rock in the middle. The study found that great white sharks can hunt using both area-restricted search and patrolling state of locomotion. Motor state and transition appear to be a factor in mating, timing, sex, individual preference, and potential habitat. That’s because sharks are most successful in the hours after dawn, when pups are more visible and reflective water makes it easier for them to hunt. There is also some spatial segregation between the sexes in Gansbaai, with females preferring shoreline habitats and males foraging by sitting more frequently than females, but habitat complexity is also a factor in the great white shark’s hunting strategy. The authors emphasize that sharks have basically two foraging strategies and show individual preferences for specific short-term mobility strategies. This article describes the behavior of great white sharks, so that they can better study their habitat selection based on prey.
Weng, KC. ; O’Sullivan, JB. ; Lowe, CG. ; Winkler, CE. ; Dewar, H., and Block, BA, 2007. Movements, behavior and habitat preferences of juvenile white sharks Carcharodon carcharias in the eastern Pacific. Marine Ecology. Progress Series (Halstenbek), 338, 211–224. https://doi.org/10.3354/meps338211
Great white sharks still have a lot of secrets about their infancy. This article investigates habitat preferences and behavioral patterns of juvenile great white sharks. The authors and others used satellites to track six juvenile great whites in the eastern Pacific and recorded their movements for comparison. Their investigation found that sharks spend most of their time living in the current system near California and Baja California, suggesting that the area is an important nursery habitat for young white sharks. They also found that there was no large gap in the sea surface temperature data for upwelling waters, where sea surface temperature varies over a much smaller range, which can be subject to error. Young white sharks move more vertically during the day, dawn and dusk than they do at night, because a lot of prey comes out at twilight, but during the full moon, more deep-sea prey comes out, so young sharks also come out during the full moon. The primary habitat for young white sharks is in the surface mixing zone, where the water is warmer. But they make extensive use of the colder waters of the thermocline. Understanding behavior of juvenile white sharks is critical to developing effective management and conservation strategies.
Lee, K. A. ; Butcher, P. A. ; Harcourt, R. G. ; Patterson, T. A. ; Peddemors, V. M. ; Roughan, M. ; Harasti, D. ; Smoothey, A. F., and Bradford, R. W., 2021. Oceanographic conditions associated with white shark (Carcharodon carcharias) habitat use along eastern Australia. Marine Ecology. Progress Series (Halstenbek), 659, 143–159. https://doi.org/10.3354/meps13572
This article described the regional distribution of white sharks and ocean conditions, and links habitat selection and behavior patterns of white sharks. The authors used satellite tracking of the effects of juvenile great whites on the habitat of juvenile and subadult white sharks off the east coast of Australia. Also they used hidden Markov models and applied generalized additive (mixed) models to estimate movement patterns and used GIS to make a map of the area where the sharks swim. Sharks preferentially choose continental sloped waters, which may be nutrient-rich. When the sea temperature was ~19 ~ 23℃, sharks were more likely to appear in region-restricted movement that means shark movement patterns affected by sea temperature. Sharks were more likely to be found with medium-high surface chlorophyll concentrations. Also, in conditions with Anticyclonic eddies off south-eastern Australia. Compared with adult sharks, juvenile sharks preferred cold-core eddies to warm-core, anticyclonic eddies. What’s interesting about the paper is that it links habitat selection for great white sharks to oceanography. This suggests that Marine conditions are also factors in white shark habitat selection, and GIS can often help to study this situation.
Weng K. C. ; Boustany, A. M. ; Pyle, P. ; Anderson, S. D. ; Brown, A., and Block, B. A., 2007. Migration and habitat of white sharks (Carcharodon carcharias) in the eastern Pacific Ocean. Marine Biology, 152(4), 877–894. https://doi.org/10.1007/s00227-007-0739-4
This paper studies the migratory distances and habitats of white sharks. The authors et al. used satellite telemetry to study the migration cycle of white sharks. They used the kernel density method to quantify the habitat of white sharks, and to measure the density of the weather. Migration routes are characterized by sounding, magnetism and gravity. The data is also used in GIS to compare the movements of individual sharks. White sharks in the eastern Pacific spend about half the year in shallow waters and the rest in distant habitats. The survey also found a migration of about 3 weeks connecting the two habitats. That explains the shark’s purposeful path. In autumn and winter, sharks avoid the surface of the water when near the habitat of pinnipeds and birds and swim at depths of up to 50 meters. It stays in the offshore focal point during spring and summer. Probably for mating and hunting game around the island. The article gave me a better understanding of how sharks migrate, that they don’t just wander around aimlessly but they migrate according to the abundance of their prey.
Boldrocchi, G. ; Kiszka, J. ; Purkis, S. ; Storai, T. ; Zinzula, L., and Burkholder, D., 2017. Distribution, ecology, and status of the white shark, Carcharodon carcharias, in the Mediterranean Sea. Reviews in Fish Biology and Fisheries, 27(3), 515–534. https://doi.org/10.1007/s11160-017-9470-5
White sharks are also found in the Mediterranean and have come into contact with humans. This paper describes the occurrence and distribution of white sharks in the Mediterranean Sea, and the spatial and seasonal distribution of white sharks. At the same time, the ecological niche of white shark was analyzed. The authors recorded sightings of great white sharks and analyzed them with satellite imagery at night. Great white shark records were mapped using ArcGIS. GIS can help to identify larger urban centers and metropolises with an area of 455 square kilometers. For each recorded white shark location, the shortest distance to the nearest urban center and the shortest distance to the nearest metropolitan area were measured in kilometers. White sharks are more common in the western Mediterranean, especially in the Adriatic and Sicilian Straits, and are observed more frequently during the summer months. The survey found that white sharks are more common in the western Mediterranean, especially in the Adriatic Sea and the Sicilian Strait. Higher productivity was associated with these areas, which are important breeding and feeding grounds for tuna and are observed more frequently in the summer, but with some bias. The study also found that white sharks moved from the Sea of Marmara and the Bosphorus region to the Aegean Sea to feed on cetacean prey after the collapse of tuna populations, suggesting they switched prey. The authors highlight a decline in the average length of white sharks in the Mediterranean, where populations have declined. This helps white shark conservation and habitat selection. It’s a better way to predict where white sharks are going to move.
Towner, A. V. ; Kock, A. A. ; Stopforth, C. ; Hurwitz, D., and Elwen, S. H., 2023. Direct observation of killer whales preying on white sharks and evidence of a flight response. Ecology (Durham), 104(1), e3875–n/a. https://doi.org/10.1002/ecy.3875
This article described the predation relationship between killer whales and white sharks . The authors used drone footage of killer whales hunting white sharks to document the behavior of killer whales and white sharks. They found that killer whales targeted great white sharks. And show some hunting skills. It also found that when the killer whales finished killing the great whites, other great whites left the area and did not return for a short time. What helps me with this article is that white sharks’ habitat choices change when they collide with other top predators. When it comes to killer whales, which are capable of killing white sharks, they leave their habitat for long periods of time. This is all the more helpful for the secret of white shark habitat selection.
Brown, A. C. ; Lee, D. E. ; Bradley, R. W., and Anderson, S., 2010. Dynamics of White Shark Predation on Pinnipeds in California: Effects of Prey Abundance. Copeia, 2010(2), 232–238. https://doi.org/10.1643/CE-08-012
This article evaluates white shark hunting trends in relation to prey. The authors and others examined shark attack records and compared prey abundance in Southeast Farallón Island of California. The survey found that shark attacks are affected by the time and date of the season, tide height and pinnipeds population. The functional response to shark attacks increases with the abundance of Northern elephant seals until a plateau is reached at higher levels of prey density. As pinnipeds saturate the waters around the island, they are more likely to spot sharks by increasing their observations, so they are more likely to come out at dusk. Adding shark populations to the inverse function model of northern elephant seal abundance shows that the functional response to shark attacks increases with the abundance of northern elephant seal. This article makes it clear that white sharks switch destinations, their habitats, and the prey that will follow them, depending on prey abundance. Understanding them can ease the conflict between humans and sharks.
Heithaus, M. R. ; Dill, L. M. ; Marshall, G. J., and Buhleier, B., 2002. Habitat use and foraging behavior of tiger sharks (Galeocerdo cuvier) in a seagrass ecosystem. Marine Biology, 140(2), 237–248. https://doi.org/10.1007/s00227-001-0711-7
This article mainly describes the habitat preference of tiger sharks and how it preys in the local habitat. The authors et al. used acoustic telemetry and animal-carried cameras to probe tiger shark habitats and the habitat conditions they inhabit. The ratio of observation time per individual in each habitat was compared with a random walk to determine tiger shark habitat preferences. The study found that tiger sharks prefer seagrass habitats. Because not only is there plenty of prey but it also helps the tiger sharks get close to it. This is helpful to study the environmental conditions of shark habitat selection, because sharks will make reasonable use of local habitat conditions.
Andrzejaczek, S.; Gleiss, A. C. ; Jordan, L.K. B. ; Pattiaratchi, C. B. ; Howey, L. A. ; Brooks, E. J., and Meekan, M. G., 2018. Temperature and the vertical movements of oceanic whitetip sharks, Carcharhinus longimanus. Scientific Reports, 8(1), 8351–12. https://doi.org/10.1038/s41598-018-26485-3
Sharks, as efficient hunters, need an internal thermal system to keep them active in the open ocean. The authors et al used satellite tags to investigate the role of temperature in the vertical movement of whitetip sharks. They used Spectral analysis and linear mixed modeling to investigate the effects of SST ( sea surface temperature) and mixed layer depth on shark movement and to model the relationship between depth and SST. It was found that the oscillation amplitude and period length decreased in winter when the water column was cold and well mixed. During this time, sharks move in the water column above 50 meters. Summer, on the other hand, increases in temperature alters vertical motion, which leads to the sharks’ thermoregulation strategy. This article can help to study the movement patterns and physiology of sharks. To better understand the effects of temperature on sharks. Whitetip sharks and great whites, both pelagic sharks, also change their locations in response to temperature, helping with habitat selection.
Cartamil, D. ; Wegner, N.C. ; Aalbers, S. ; Sepulveda, C.A. ; Baquero, A. ; Graham, J.B., 2010. Diel movement patterns and habitat preferences of the common thresher shark ( Alopias vulpinus ) in the Southern California Bight. Marine and Freshwater Research, 61(5), 596–604. https://doi.org/10.1071/MF09153
Thresher sharks are an important shark fishery in California, and understanding their habits is crucial. This article describes thresher shark movement patterns and habitat preferences in the Southern California Bay. The authors used acoustic telemetry to track sharks, as well as to detect the connection between water depth and temperature. The shark movement data uses GIS to map the depth of water in the study area and determine the movement rate for comparison at the time of day. The study found that sharks prefer areas on continental slopes, offshore basins and undersea canyons where other prey such as sardines are abundant. It’s one of the reasons sharks like to be active during the day. Higher turbidity offshore helps thresher sharks hunt with their long tails. This paper shows that thresher shark habitat preferences are still determined by prey, and that natural conditions can protect young sharks from predators. To better understand the selection conditions for sharks’ habitat preferences.
Coxon, J. L. ; Butcher, P. A. ; Spaet, J. L. Y.,and Rizzari, J. R., 2022. Preliminary Data about Habitat Use of Subadult and Adult White Sharks ( Carcharodon carcharias ) in Eastern Australian Waters. Biology (Basel, Switzerland), 11(10), 1443. https://doi.org/10.3390/biology11101443
This article described the motor behavior and habitat of subadult and adult white sharks used in tropical and temperate waters of eastern Australia. The authors tagged three white sharks, from subadult to adult. Record the depth of your dive, where you swim, and the temperature of your water. The sample great white shark activity areas were tagged with GIS and their horizontal and vertical movements were calculated. The study found that all sharks preferred offshore habitats and stayed in the 50-meter water column, diving during the day. There are some differences between individuals, with the first two segments in the midstream and the upstream segment only after reaching the destination southward. And the other one prefers the upper stream, but the main goal is to select the habitat that they’re in and have their favorite prey, some bottom-dwelling fish. All sharks have similar latitude and longitudinal range. This is essential for the use of space by sharks and for the management of jurisdictions, as well as promoting shark conservation.
Dicken, M. L. ; Hussey, N. E. ; Christiansen, H. M ; Smale, M. J. ; Nkabi, N. ; Cliff, G. ; Wintner, S. P., and Valentine, J. F., 2017. Diet and trophic ecology of the tiger shark (Galeocerdo cuvier) from South African waters. PloS One, 12(6), e0177897–e0177897. https://doi.org/10.1371/journal.pone.0177897
Understanding the diet and nutritional ecology of tiger sharks can lead to effective management measures. In this paper, the diet of tiger sharks was investigated using stomach contents data and stable isotope analysis (δ15N and δ13C). The study found that tiger sharks have a very broad diet, and as they get larger, they have a greater need for larger prey. And the tiger shark’s diet changes seasonally, especially depending on whale carcasses. This causes the tiger shark to move over a wide range and forage in a vertical range, exhibiting yo-yo diving behavior. What helped me with this article was that it allowed me to understand the dietary distribution of sharks. We can better determine the habitat selection of sharks by looking at their prey.
Thank you for reading!