skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Persistence of giants: population dynamics of the limpet Scutellastra laticostata on rocky shores in Western Australia
Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m -2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m -2 ), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr -1 at the notch to 0.79 and 0.87 yr -1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L ∞ , von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.  more » « less
Award ID(s):
1831937
PAR ID:
10198189
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Marine Ecology Progress Series
Volume:
646
ISSN:
0171-8630
Page Range / eLocation ID:
79 to 92
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Geological Society of America Abstracts with Programs)
    null (Ed.)
    We studied the population and size distribution of the parasitic foraminifer Cibicides antarcticus living on the shell of the Antarctic scallop Adamussium colbecki within Explorers Cove, Western McMurdo Sound, Antarctica. Previous work examined populations and parasite load between two distinct geographic locations, but our study focuses on the population and size distribution of C. antarcticus within one embayment, Explorers Cove. We hypothesize that if A. colbecki are living in the same embayment and have one recruitment event, then populations and their size distributions should be similar; but, if they have differing populations and sizes, they likely are recruiting from very localized microhabitats with varying recruitment events. Live A. colbecki were collected from the Jamesway (water depth 24.4 m), Smallberg (9.1 m), and Anoxic Pit (9.1 m) sites in Explorers Cove. Five top valves were examined for C. antarcticus under 75x magnification. The foraminifera were counted, their spatial distribution noted, and their largest diameter was measured using ImageJ. All data from each site was pooled to compare the sites. Results indicate that all the sites had different populations of parasitic C. antarcticus. Smallberg had the most parasitic foraminifera (n = 663), followed by Jamesway (n = 319); the Anoxic Pit site had the fewest (n = 55). The largest size classes (0.70–1.30 mm) occurred at the Anoxic Pit and Smallberg sites, while the smallest size classes (0.18–0.70 mm) were found at Jamesway, the deepest site. The average size of Cibicides was also smaller at Jamesway (0.71 mm), compared to Smallberg (0.92 mm), and Anoxic Pit (0.94 mm). In general, C. antarcticus recruits to the youngest part of the scallop shell while larger adults are found on oldest part of the shell. The skewed size frequency distributions and differing population sizes suggest that C. antarcticus has localized microhabitat recruitment in Explorers Cove, rather than one synchronous recruitment event. 
    more » « less
  2. ; ; (, Geological Society of America Abstracts with Programs)
    null (Ed.)
    NOTE: COVID CANCELLED THE SOUTHEASTERN MEETING AND THEY TOLD US TO SUBMIT OUR ABSTRACT AGAIN TO THE NATIONAL MEETING; THIS IS THE NATIONAL MEETING ABSTRACT WHERE KIRSTEN PRESENTED HER TALK. We studied the population and size distribution of the parasitic foraminifer Cibicides antarcticus living on the shell of the Antarctic scallop Adamussium colbecki within Explorers Cove, western McMurdo Sound, Antarctica. Previous work examined populations and parasite load between two distinct geographic locations, but our study focuses on the population and size distribution of C. antarcticus within one embayment, Explorers Cove. We hypothesize that if A. colbecki are living in the same embayment and has one recruitment event, then C. antarcticus populations and their size distributions should be similar; but, if they have differing populations and sizes, they likely are recruiting from very localized microhabitats with varying recruitment events. Live A. colbecki were collected from three sites in Explorers Cove: Jamesway (water depth 24.4 m), Smallberg (9.1 m), and Anoxic Pit (9.1 m). Five top valves from each site were examined for C. antarcticus under 75x magnification. The foraminifera were counted, their spatial distribution noted, and their largest diameter was measured using ImageJ. All data from each site was pooled to compare the sites. Results indicate that all the sites had different populations of parasitic C. antarcticus. Smallberg had the most parasitic foraminifera (n = 663), followed by Jamesway (n = 319) and the Anoxic Pit site had the fewest (n = 55). The largest size classes (0.70–1.30 mm) occurred at Anoxic Pit and Smallberg, while the smallest size classes (0.18–0.70 mm) were found at Jamesway, the deepest site. The average size of Cibicides was also smaller at Jamesway (0.73 mm) compared to Smallberg (0.89 mm) and Anoxic Pit (0.91 mm). In general, C. antarcticus recruits to the youngest part of the scallop shell while larger adults are found on the oldest part of the shell. The skewed size frequency distributions and differing population sizes suggest that C. antarcticus has localized microhabitat recruitment in Explorers Cove, rather than one synchronous recruitment event. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Marine Ecology Progress Series)
    Mass mortality events, due to a variety of natural and anthropogenic causes, usually result in population (and associated fishery) crashes. Recovery from such events may not occur for many years, if at all. We have witnessed a mass die-off of adult (1+ yr) bay scallops Argopecten irradians irradians in the Peconic Bays, New York, USA, from 2019-2022, with declines in population density from spring to fall of 90-99%. Similar declines in commercial landings have occurred since 2018, with severe economic consequences for fishermen. Observed mortality levels are well above those seen prior to 2019. However, since die-offs of adult scallops have been occurring after the first seasonal spawning cycle, larval and benthic juvenile (0+ yr) recruitment have remained robust through 2021. Nevertheless, with lower numbers of adults surviving to spawn in September-October, resulting in fewer fall recruits, potential buffering of marked annual fluctuations in abundance is now less likely for this short-lived species. Peconic bay scallops are again in a precarious state as these recurring die-offs, likely driven by changing environmental conditions, present further challenges to the persistence of robust populations and the likelihood of successful restoration efforts. 
    more » « less
  4. ; ; ; ; ; ; (, New Zealand Journal of Marine and Freshwater Research)
    Alfaro, Andrea C; Ragg, Norman; Venter, Leonie (Ed.)
    Understanding the recruitment dynamics of invertebrates in kelp forests is critical to informing climate-ready restoration. Here we examine abalone and sea urchin recruitment (3–20 mm in size) patterns in northern California across a period of drastic change. Annual surveys were conducted before, during and after the MHW (2014–2016), the loss of a major predatory sea star (2012–2016) and the collapse of a bull kelp forest in 2014. Divers surveyed artificial reef recruitment modules (n = 12) over 20 years in an area that once supported dense bull kelp, Nereocystis leutkeana, forests and the world's largest recreational abalone fishery. From 2016 to 2022, we tracked the decline of red abalone, Haliotis rufescens, recruitment and the rise of purple sea urchin, Strongylocentrotus purpuratus, recruitment. Adult densities of purple sea urchins increased as did newly settled sea urchins (<3 mm), while adult and newly settled red abalone declined. Eight years after the kelp forest collapse, red abalone recruitment remained low and sea urchin recruitment continued to increase. Recruitment patterns can inform both abalone restoration targets and sea urchin dynamics as part of a more holistic kelp forest recovery plan that is responsive to climate change drivers. 
    more » « less
  5. ; (, Frontiers in Marine Science)
    Recruitment is a key demographic process for maintenance of local populations and recovery following disturbance. For marine invertebrates, distribution and abundances of recruits are impacted by spatiotemporal variation in larval supply, settlement rates and post-settlement survival. However, for colonial and modular organisms, differences in survival and growth between settlers and colonial recruits may also affect recruitment patterns. In the Caribbean, shifts in the benthic community structure favoring octocoral’s have been detected, and recruitment has been suggested as key for octocoral’s resilience. Hence, we studied octocoral recruitment dynamics, and evaluated the role of pre-settlement, settlement and post-settlement processes in recruit’s densities. We performed the study at two sites with different octocoral densities, on the south coast of St. John, United States Virgin Islands, and distinguished between processes occurring to recently settled polyps and to colonial recruits. At both sites, we monitored P. homomalla settlers on settlement tiles for 3 months, and colonial recruits of two of the most abundant genera ( Eunicea and Pseudoplexaura) for 3 years. In addition, we assessed whether recruits morphological traits affected recruitment and divided recruits of the genus Eunicea based on the presence of large calyces. The major contributor to both, single-polyps and colonial recruit densities was larval supply. Single-polyp densities were not limited by the availability of space, settlement cues, or early post-settlement survival. Height was the only predictor of survival and growth of colonial recruits, with potential growth rates increasing with height. However, large recruits suffered partial mortality often, distorting the relationship between recruit age and size, and causing most recruits to remain in the recruit size class (≤5 cm) longer than a year. Octocorals have been resilient to the conditions that have driven the decline of scleractinian corals throughout the Caribbean, and recruitment has been key to that success. Our results are crucial to understand early life history dynamics of Caribbean octocorals, and highlights the need to standardize the definition of recruit among colonial and modular taxa to facilitate inter-specific comparisons, and to understand future changes in coral reef community assemblages. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email