Caribbean Sea Soundscapes: Monitoring Humpback Whales, Biological Sounds, Geological Events, and Anthropogenic Impacts of Vessel Noise

Humpback whale (Megaptera novaeangliae) distribution in the eastern Caribbean Sea was studied by means of solitary sonobuoys deployed from an oceanographic aircraft. Humpback whale sounds were detected on 33 of 82 sonobuoys deployed. It is estimated that 62 whales were detected in an area of 22 140 km2 by this method with whale density calculated at 2.8 × 10−3 whales/km2. For further experiments in selected areas we used a colinear array to obtain accurate counts of humpbacks. A total of 18 humpbacks were detected in this manner with a mean of 2.6 whales per array deployment. Combined acoustic and visual detections indicate a minimum of 119 humpbacks in the area surveyed. This rapid acoustic method could also be applied to detection of almost all odontocete cetaceans and to other marine mammals with distinctive vocal patterns. Key words: cetaceans, whales, acoustic detection, distribution, density, humpbacks, aircraft detectors, sonobuoys

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Author response: Vessel noise levels drive behavioural responses of humpback whales with implications for whale-watching

10.7554/elife.56760.sa2 ◽

2020 ◽

Author(s):

Kate R Sprogis ◽

Simone Videsen ◽

Peter T Madsen

Keyword(s):

Author Response ◽

Humpback Whales ◽

Noise Levels ◽

Whale Watching ◽

Behavioural Responses ◽

Vessel Noise

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The effects of vessel noise on the communication network of humpback whales

Royal Society Open Science ◽

10.1098/rsos.190967 ◽

2019 ◽

Vol 6 (11) ◽

pp. 190967 ◽

Cited By ~ 1

Author(s):

Rebecca A. Dunlop

Keyword(s):

Communication Network ◽

Social Interactions ◽

Social Behaviour ◽

Separation Distance ◽

Humpback Whales ◽

Social Signals ◽

Wind Noise ◽

Physical Presence ◽

Communication Space ◽

Vessel Noise

Humpback whales rely on acoustic communication to mediate social interactions. The distance to which these social signals propagate from the signaller defines its communication space, and therefore communication network (number of potential receivers). As humpback whales migrate along populated coastlines, they are likely to encounter noise from vessel traffic which will mask their social signals. Since no empirical data exist on baleen whale hearing, the consequences of this are usually assumed, being the modelled reduction in their communication space. Here, the communication space and network of migrating humpback whales was compared in increasing wind-dominated and vessel-dominated noise. Behavioural data on their social interactions were then used to inform these models. In typical wind noise, a signaller's communication space was estimated to extend to 4 km, which agreed with the maximum separation distance between groups that socially interacted. An increase in vessel noise reduced the modelled communication area, along with a significant reduction in group social interactions, probably due to a reduction in their communication network. However, signal masking did not fully explain this change in social behaviour, implying there was also an additional effect of the physical presence of the vessel on signaller and receiver behaviour. Though these observed changes in communication space and social behaviour were likely to be short term and localized, an increase in vessel activity due to tourism and coastal population growth may cause more sustained changes along the humpback whale migration paths.

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Vessel noise levels drive behavioural responses of humpback whales with implications for whale-watching

eLife ◽

10.7554/elife.56760 ◽

2020 ◽

Vol 9 ◽

Author(s):

Kate R Sprogis ◽

Simone Videsen ◽

Peter T Madsen

Keyword(s):

Low Frequency ◽

Humpback Whales ◽

Noise Levels ◽

Whale Watching ◽

Noise Emission ◽

Sensory Stimuli ◽

Fitness Consequences ◽

Controlled Exposure ◽

Vessel Noise ◽

The Impact

Disturbance from whale-watching can cause significant behavioural changes with fitness consequences for targeted whale populations. However, the sensory stimuli triggering these responses are unknown, preventing effective mitigation. Here, we test the hypothesis that vessel noise level is a driver of disturbance, using humpback whales (Megaptera novaeangliae) as a model species. We conducted controlled exposure experiments (n = 42) on resting mother-calf pairs on a resting ground off Australia, by simulating whale-watch scenarios with a research vessel (range 100 m, speed 1.5 knts) playing back vessel noise at control/low (124/148 dB), medium (160 dB) or high (172 dB) low frequency-weighted source levels (re 1 μPa RMS@1 m). Compared to control/low treatments, during high noise playbacks the mother’s proportion of time resting decreased by 30%, respiration rate doubled and swim speed increased by 37%. We therefore conclude that vessel noise is an adequate driver of behavioural disturbance in whales and that regulations to mitigate the impact of whale-watching should include noise emission standards.

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Justification of the need to increase the fertility of reclaimed alluvial soils of JSC «Moskovskoe»

Melioration and Water Management ◽

10.32962/0235-2524-2019-5-44-48 ◽

2020 ◽

pp. 44-48

Author(s):

Andrey ilinsky ◽

Alexander Nefedov ◽

Konstantin Evsenkin

Keyword(s):

Organic Matter ◽

Agricultural Land ◽

Crop Yields ◽

Anthropogenic Impacts ◽

Fertility Restoration ◽

Research Work ◽

Alluvial Soils ◽

Ecological Stability ◽

Reclaimed Land ◽

Adverse Weather

Global climatic changes, technogenic pollution by pollutants, violations of technologies of exploitation of reclaimed land lead to a decrease in fertility and soil degradation of agricultural land. Adverse weather conditions, resulting in a lack of adequate flood water, and economic difficulties in agriculture make it difficult to fill the deficit of organic matter and macronutrients in reclaimed alluvial soils. The monitoring of agrochemical properties of alluvial meadow medium-loamy soil of the stationary site (reclaimed lands of JSC «Moskovskoye» of Ryazan region), located in the floodplain of the Oka river, conducted by the Meshchersky branch of Vniigim, showed the presence and intensification of degradation changes in the soil. Thus, comparing the agrochemical indicators in the layer 0–20 cm, carried out in 1995, with the indicators of 2019, it should be noted a decrease in soil fertility. The decrease in soil quality was expressed in a decrease in the amount of mobile phosphorus by 37.6 %, mobile potassium by 53.3 %. Also, during this time there was a decrease in organic matter by 9.1 %, and an increase in soil acidity was 0.6 pH. As a result of such changes, soils lose ecological stability and become more vulnerable to adverse weather and negative anthropogenic impacts. In such a situation, advanced agricultural techniques should be actively used to obtain guaranteed, environmentally safe crop yields and restore the fertility of degraded reclaimed soils. In this regard, there is a need to develop innovative methods of fertility restoration of degraded alluvial soils in reclaimed lands using multi-component organic-mineral ameliorants. Meshchersky branch performs research work in addressing this issue.

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Role of the eastern Pacific-Caribbean Sea SST gradient in the Choco low-level jet variations from 1900–2015

Climate Research ◽

10.3354/cr01633 ◽

2021 ◽

Author(s):

WL Cerón ◽

RV Andreoli ◽

MT Kayano ◽

A Avila-Diaz

Keyword(s):

Caribbean Sea ◽

Eastern Pacific ◽

Low Level ◽

Low Level Jet ◽

Sst Gradient

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Submergence, nutrient enrichment, and tropical storm impacts on Spartina alterniflora in the microtidal northern Gulf of Mexico

Marine Ecology Progress Series ◽

10.3354/meps13342 ◽

2020 ◽

Vol 644 ◽

pp. 33-45

Author(s):

JM Hill ◽

PS Petraitis ◽

KL Heck

Keyword(s):

Gulf Of Mexico ◽

Sea Level Rise ◽

Sea Level ◽

Spartina Alterniflora ◽

Anthropogenic Impacts ◽

Interactive Effects ◽

Relative Sea Level ◽

Hurricane Disturbance ◽

Submergence Stress ◽

Relative Sea Level Rise

Salt marshes face chronic anthropogenic impacts such as relative sea level rise and eutrophication, as well as acute disturbances from tropical storms that can affect the productivity of these important communities. However, it is not well understood how marshes already subjected to eutrophication and sea level rise will respond to added effects of episodic storms such as hurricanes. We examined the interactive effects of nutrient addition, sea level rise, and a hurricane on the growth, biomass accumulation, and resilience of the saltmarsh cordgrass Spartina alterniflora in the Gulf of Mexico. In a microtidal marsh, we manipulated nutrient levels and submergence using marsh organs in which cordgrasses were planted at differing intertidal elevations and measured the impacts of Hurricane Isaac, which occurred during the experiment. Prior to the hurricane, grasses at intermediate and high elevations increased in abundance. After the hurricane, all treatments lost approximately 50% of their shoots, demonstrating that added nutrients and elevation did not provide resistance to hurricane disturbance. At the end of the experiment, only the highest elevations had been resilient to the hurricane, with increased above- and belowground growth. Added nutrients provided a modest increase in above- and belowground growth, but only at the highest elevations, suggesting that only elevation will enhance resilience to hurricane disturbance. These results empirically demonstrate that S. alterniflora in microtidal locations already subjected to submergence stress is less able to recover from storm disturbance and suggests we may be underestimating the loss of northern Gulf Coast marshes due to relative sea level rise.

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