Evidence for Increases in Antarctic Blue Whales Based on Bayesian Modelling

Branch, Trevor A.; Matsuoka, Koji; Miyashita, Tomio

doi:10.1111/j.1748-7692.2004.tb01190.x

Cited by 170 publications

(208 citation statements)

References 37 publications

Supporting

Mentioning

201

Contrasting

Order By: Relevance

“…The relatively high encounter rate of minke whales (SR = 0.031) suggests that this species is far more abundant than any other large whale species off northeastern Brazil. This was expected considering that minke whale density indices had not decreased in the area during whaling (DA ROCHA 1983, OHSUMI & MYASHITA 1987 and it is well known that other species have been severely depleted by whaling (CLAPHAM et al 1999, PERRY et al 1999, BRANCH et al 2004.…”

Section: Discussionmentioning

confidence: 99%

Distribution and relative abundance of large whales in a former whaling ground off eastern South America

Andriolo¹,

Rocha²,

Zerbini³

et al. 2010

Zoologia (Curitiba, Impr.)

View full text Add to dashboard Cite

Ship-based sighting surveys for cetaceans were conducted in the former whaling ground off the northeastern coast of Brazil. The cruises took place in winter and spring of 1998-2001 with the objectives of investigating current distribution and abundance of cetaceans, particularly large whale species taken during whaling. In 1998 the survey were conducted between the parallels 5°30'W and 9°S and the 200 m isobath and the meridian 033°W. A total of about 3,100 nm were surveyed between 1998 and 2001 Surveys were conducted using line transect methods from about 5-10°S, and from the coast to 33°W. A total of 151 sightings (203 individuals) of large whales were recorded on effort. The Antarctic minke whale - Balaenoptera bonaerensis (Burmeister, 1867) was the most frequently sighted species (97 groups/132 individuals; Sighting Rate [SR] = 0.031 groups/nm), being recorded only in offshore waters. Density gradually increased from August to October. Minke whales were distributed throughout the area, both to the north and the south of former whaling ground. Sighting data indicate this is the most abundant species, particularly in the area beyond the continental shelf break. Breeding behavior was observed for Antarctic minke whales, but few groups containing calves were recorded (4.3% of the groups sighted on effort). Three other large whale species were recorded in low numbers: the Bryde's whale - Balaenoptera edeni (Anderson, 1879)¹; the sei whale, B. borealis (Lesson, 1828), and the sperm, Physeter macrocephalus (Linnaeus, 1758). Sei, Bryde and sperm whales were regularly caught during whaling operations, but are rare in the area, suggesting they were depleted by whaling and have yet to recover to their pre-explotation abundance. In contrast, minke whales are abundant in this area, suggesting that either they were not substantially depleted, or that they have recovered rapidly. Blue whale, Balaenoptera musculus (Linnaeus, 1758), and fin whale, B. physalus (Linnaeus, 1758), not recorded on our surveys, have always been extremely rare in the area

show abstract

Section: Discussionmentioning

confidence: 99%

Distribution and relative abundance of large whales in a former whaling ground off eastern South America

Andriolo¹,

Rocha²,

Zerbini³

et al. 2010

Zoologia (Curitiba, Impr.)

View full text Add to dashboard Cite

show abstract

“…Southern right whales Eubalaena australis, Western Arctic bowhead whales Balaena mysticetus ( Figure 2a) and Northeast Pacific gray whales Eschrichtius robustus], whereas others remained at low population levels [25,33,34]. In 1986, the International Whaling Commission expanded the commercial whaling moratorium to all great whales, leading to increases in other species, such as sperm Physeter macrocephalus [35] and blue whales Balaenoptera musculus [36]. Similarly, several populations of pinnipeds and other marine mammals started to increase after the hunting for fur, skin, blubber, ivory or bounty was either prohibited or reduced [3] (Anna M. Magera, MSc thesis, Dalhousie University, 2011).…”

Section: Marine Mammalsmentioning

confidence: 99%

Recovery of marine animal populations and ecosystems

Lotze¹,

Coll²,

Magera³

et al. 2011

Trends in Ecology & Evolution

358

316

View full text Add to dashboard Cite

Many marine populations and ecosystems have experienced strong historical depletions, yet reports of recoveries are increasing. Here, we review the growing research on marine recoveries to reveal how common recovery is, its magnitude, timescale and major drivers. Overall, 10-50% of depleted populations and ecosystems show some recovery, but rarely to former levels of abundance. In addition, recovery can take many decades for long-lived species and complex ecosystems. Major drivers of recovery include the reduction of human impacts, especially exploitation, habitat loss and pollution, combined with favorable life-history and environmental conditions. Awareness, legal protection and enforcement of management plans are also crucial. Learning from historical recovery successes and failures is essential for implementing realistic conservation goals and promising management strategies.A new focus on recovery An increasing number of studies have reported strong declines in marine animal populations and the degradation of ocean ecosystems over past decades and centuries around the world [1][2][3][4][5][6][7], leading to a widespread perception of empty oceans and polluted waters. Yet, throughout history, humans have responded to declining resource abundance and ecosystem degradation by implementing management and conservation measures. Some of these have been successful and resulted in recovery, whereas others have failed [3,8,9].Therefore, an important question to science and management is: how common is recovery among depleted populations and degraded ecosystems in the ocean? Today, many marine mammal, bird, reptile and fish populations are at low abundance, and several species are endangered or extinct on regional or global scales [5,[10][11][12]. However, despite long periods of intense human impacts, most marine species persist and some populations do show signs of recovery [3,8,9]. Similarly, many coastal habitats, including wetlands, seagrass beds, mangrove and kelp forests, and oyster and coral reefs, have been severely reduced or degraded [2][3][4]6], yet partial recovery has been achieved in some regions in response to protection and pollution controls [3,13]. Restoration attempts at an ecosystem level have often been followed by the return and recovery of former species assemblages and ecosystem functions [13][14][15][16][17], but some ecosystems have remained in an altered state [18]. Such successes could serve as important guides for efforts to prevent further biodiversity loss and enhance future recoveries.Despite a growing number of case studies on the recovery of specific populations or ecosystems, an overview of the general patterns and drivers of marine recoveries over historical timescales is lacking. A recent review on the recovery of damaged ecosystems found that many terrestrial and marine ecosystems can recover on timescales of a few years to a few decades after major perturbations [19]. However, most case studies in the review, especially among marine and brackish examples, included small, short-...

show abstract

“…In addition, more research is needed on the mechanisms that link the physical variables to ecological processes. Beyond that there is a need to consider ecological scenarios, including the effects of the recovery of over-exploited baleen whale populations (Branch et al, 2004;Noad et al, 2011;Tulloch et al, 2017) toward fully integrated system understanding. Future fishery scenarios are also required to explore how demand may change over time.…”

Section: Future Workmentioning

confidence: 99%

A Synergistic Approach for Evaluating Climate Model Output for Ecological Applications

et al. 2017

View full text Add to dashboard Cite

Increasing concern about the impacts of climate change on ecosystems is prompting ecologists and ecosystem managers to seek reliable projections of physical drivers of change. The use of global climate models in ecology is growing, although drawing ecologically meaningful conclusions can be problematic. The expertise required to access and interpret output from climate and earth system models is hampering progress in utilizing them most effectively to determine the wider implications of climate change. To address this issue, we present a joint approach between climate scientists and ecologists that explores key challenges and opportunities for progress. As an exemplar, our focus is the Southern Ocean, notable for significant change with global implications, and on sea ice, given its crucial role in this dynamic ecosystem. We combined perspectives to evaluate the representation of sea ice in global climate models. With an emphasis on ecologically-relevant criteria (sea ice extent and seasonality) we selected a subset of eight models that reliably reproduce extant sea ice distributions. While the model subset shows a similar mean change to the full ensemble in sea ice extent (approximately 50% decline in winter and 30% decline in summer), there is a marked reduction in the range. This improved the precision of projected future sea ice distributions by approximately one third, and means they are more amenable to ecological interpretation. We conclude that careful multidisciplinary evaluation of climate models, in conjunction with ongoing modeling advances, should form an integral part of utilizing model output.

show abstract

Evidence for Increases in Antarctic Blue Whales Based on Bayesian Modelling

Cited by 170 publications

References 37 publications

Distribution and relative abundance of large whales in a former whaling ground off eastern South America

Distribution and relative abundance of large whales in a former whaling ground off eastern South America

Recovery of marine animal populations and ecosystems

A Synergistic Approach for Evaluating Climate Model Output for Ecological Applications

Contact Info

Product

Resources

About