Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave

Mads S. Thomsen, Luca Mondardini, Tommaso Alestra, Shawn Gerrity, Leigh Tait, Paul M. South, Stacie A. Lilley, David R. Schiel

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Detailed research has documented gradual changes to biological communities attributed to increases in global average temperatures. However, localized and abrupt temperature anomalies associated with heatwaves may cause more rapid biological changes. We analyzed temperature data from the South Island of New Zealand and investigated whether the hot summer of 2017/18 affected species of bull kelp, Durvillaea antarctica, D. poha, and D. willana. Durvillaea spp. are large iconic seaweeds that inhabit the low intertidal zone of exposed coastlines, where they underpin biodiversity and ecosystem functioning. Sea surface temperatures (SST) during the summer of 2017/18 included the strongest marine heatwaves recorded in 38 years of existing oceanic satellite data for this region. Air temperatures were also high, and, coupled with small wave heights, resulted in strong desiccation stress during daytime low tides. BeforeAfter analysis of drone images of four reef platforms (42, 42, 44, and 45 degrees S) was used to evaluate changes to bull kelp over the hot summer. Bull kelp loss varied among species and reefs, with the greatest (100%) loss of D. poha at Pile Bay in Lyttelton Harbor (44 degrees S). In Pile Bay, SST exceeded 23 degrees C and air temperatures exceeded 30 degrees C, while Durvillaea was exposed for up to 3 h per day during low tide. Follow-up surveys showed that all bull kelps were eliminated from Pile Bay, and from all reefs within and immediately outside of Lyttelton Harbor. Following the localized extinction of bull kelp in Pile Bay, the invasive kelp Undaria pinnatifida recruited in high densities (average of 120 m(-2)). We conclude that bull kelps are likely to experience additional mortalities in the future because heatwaves are predicted to increase in magnitude and durations. Losses of the endemic D. poha are particularly concerning due to its narrow distributional range.

Original languageEnglish
Article number84
Number of pages10
JournalFrontiers in Marine Science
Volume6
DOIs
Publication statusPublished - 6 Mar 2019

Cite this

Thomsen, M. S., Mondardini, L., Alestra, T., Gerrity, S., Tait, L., South, P. M., ... Schiel, D. R. (2019). Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave. Frontiers in Marine Science, 6, [84]. https://doi.org/10.3389/fmars.2019.00084
Thomsen, Mads S. ; Mondardini, Luca ; Alestra, Tommaso ; Gerrity, Shawn ; Tait, Leigh ; South, Paul M. ; Lilley, Stacie A. ; Schiel, David R. / Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave. In: Frontiers in Marine Science. 2019 ; Vol. 6.
@article{115653d71f5f4bdbb50608101d1b224d,
title = "Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave",
abstract = "Detailed research has documented gradual changes to biological communities attributed to increases in global average temperatures. However, localized and abrupt temperature anomalies associated with heatwaves may cause more rapid biological changes. We analyzed temperature data from the South Island of New Zealand and investigated whether the hot summer of 2017/18 affected species of bull kelp, Durvillaea antarctica, D. poha, and D. willana. Durvillaea spp. are large iconic seaweeds that inhabit the low intertidal zone of exposed coastlines, where they underpin biodiversity and ecosystem functioning. Sea surface temperatures (SST) during the summer of 2017/18 included the strongest marine heatwaves recorded in 38 years of existing oceanic satellite data for this region. Air temperatures were also high, and, coupled with small wave heights, resulted in strong desiccation stress during daytime low tides. BeforeAfter analysis of drone images of four reef platforms (42, 42, 44, and 45 degrees S) was used to evaluate changes to bull kelp over the hot summer. Bull kelp loss varied among species and reefs, with the greatest (100{\%}) loss of D. poha at Pile Bay in Lyttelton Harbor (44 degrees S). In Pile Bay, SST exceeded 23 degrees C and air temperatures exceeded 30 degrees C, while Durvillaea was exposed for up to 3 h per day during low tide. Follow-up surveys showed that all bull kelps were eliminated from Pile Bay, and from all reefs within and immediately outside of Lyttelton Harbor. Following the localized extinction of bull kelp in Pile Bay, the invasive kelp Undaria pinnatifida recruited in high densities (average of 120 m(-2)). We conclude that bull kelps are likely to experience additional mortalities in the future because heatwaves are predicted to increase in magnitude and durations. Losses of the endemic D. poha are particularly concerning due to its narrow distributional range.",
keywords = "canopy forming seaweed, temperature anomaly, marine heatwave, extinction, endemic species, foundation species, NEW-ZEALAND, UNDARIA-PINNATIFIDA, LESSONIA-NIGRESCENS, CLIMATE-CHANGE, COMMUNITIES, TEMPERATURE, ANTARCTICA, PHAEOPHYCEAE, SETTLEMENT, MORTALITY",
author = "Thomsen, {Mads S.} and Luca Mondardini and Tommaso Alestra and Shawn Gerrity and Leigh Tait and South, {Paul M.} and Lilley, {Stacie A.} and Schiel, {David R.}",
year = "2019",
month = "3",
day = "6",
doi = "10.3389/fmars.2019.00084",
language = "English",
volume = "6",
journal = "Frontiers in Marine Science",
issn = "2296-7745",
publisher = "Frontiers Media SA",

}

Thomsen, MS, Mondardini, L, Alestra, T, Gerrity, S, Tait, L, South, PM, Lilley, SA & Schiel, DR 2019, 'Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave' Frontiers in Marine Science, vol. 6, 84. https://doi.org/10.3389/fmars.2019.00084

Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave. / Thomsen, Mads S.; Mondardini, Luca; Alestra, Tommaso; Gerrity, Shawn; Tait, Leigh; South, Paul M.; Lilley, Stacie A.; Schiel, David R.

In: Frontiers in Marine Science, Vol. 6, 84, 06.03.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave

AU - Thomsen, Mads S.

AU - Mondardini, Luca

AU - Alestra, Tommaso

AU - Gerrity, Shawn

AU - Tait, Leigh

AU - South, Paul M.

AU - Lilley, Stacie A.

AU - Schiel, David R.

PY - 2019/3/6

Y1 - 2019/3/6

N2 - Detailed research has documented gradual changes to biological communities attributed to increases in global average temperatures. However, localized and abrupt temperature anomalies associated with heatwaves may cause more rapid biological changes. We analyzed temperature data from the South Island of New Zealand and investigated whether the hot summer of 2017/18 affected species of bull kelp, Durvillaea antarctica, D. poha, and D. willana. Durvillaea spp. are large iconic seaweeds that inhabit the low intertidal zone of exposed coastlines, where they underpin biodiversity and ecosystem functioning. Sea surface temperatures (SST) during the summer of 2017/18 included the strongest marine heatwaves recorded in 38 years of existing oceanic satellite data for this region. Air temperatures were also high, and, coupled with small wave heights, resulted in strong desiccation stress during daytime low tides. BeforeAfter analysis of drone images of four reef platforms (42, 42, 44, and 45 degrees S) was used to evaluate changes to bull kelp over the hot summer. Bull kelp loss varied among species and reefs, with the greatest (100%) loss of D. poha at Pile Bay in Lyttelton Harbor (44 degrees S). In Pile Bay, SST exceeded 23 degrees C and air temperatures exceeded 30 degrees C, while Durvillaea was exposed for up to 3 h per day during low tide. Follow-up surveys showed that all bull kelps were eliminated from Pile Bay, and from all reefs within and immediately outside of Lyttelton Harbor. Following the localized extinction of bull kelp in Pile Bay, the invasive kelp Undaria pinnatifida recruited in high densities (average of 120 m(-2)). We conclude that bull kelps are likely to experience additional mortalities in the future because heatwaves are predicted to increase in magnitude and durations. Losses of the endemic D. poha are particularly concerning due to its narrow distributional range.

AB - Detailed research has documented gradual changes to biological communities attributed to increases in global average temperatures. However, localized and abrupt temperature anomalies associated with heatwaves may cause more rapid biological changes. We analyzed temperature data from the South Island of New Zealand and investigated whether the hot summer of 2017/18 affected species of bull kelp, Durvillaea antarctica, D. poha, and D. willana. Durvillaea spp. are large iconic seaweeds that inhabit the low intertidal zone of exposed coastlines, where they underpin biodiversity and ecosystem functioning. Sea surface temperatures (SST) during the summer of 2017/18 included the strongest marine heatwaves recorded in 38 years of existing oceanic satellite data for this region. Air temperatures were also high, and, coupled with small wave heights, resulted in strong desiccation stress during daytime low tides. BeforeAfter analysis of drone images of four reef platforms (42, 42, 44, and 45 degrees S) was used to evaluate changes to bull kelp over the hot summer. Bull kelp loss varied among species and reefs, with the greatest (100%) loss of D. poha at Pile Bay in Lyttelton Harbor (44 degrees S). In Pile Bay, SST exceeded 23 degrees C and air temperatures exceeded 30 degrees C, while Durvillaea was exposed for up to 3 h per day during low tide. Follow-up surveys showed that all bull kelps were eliminated from Pile Bay, and from all reefs within and immediately outside of Lyttelton Harbor. Following the localized extinction of bull kelp in Pile Bay, the invasive kelp Undaria pinnatifida recruited in high densities (average of 120 m(-2)). We conclude that bull kelps are likely to experience additional mortalities in the future because heatwaves are predicted to increase in magnitude and durations. Losses of the endemic D. poha are particularly concerning due to its narrow distributional range.

KW - canopy forming seaweed

KW - temperature anomaly

KW - marine heatwave

KW - extinction

KW - endemic species

KW - foundation species

KW - NEW-ZEALAND

KW - UNDARIA-PINNATIFIDA

KW - LESSONIA-NIGRESCENS

KW - CLIMATE-CHANGE

KW - COMMUNITIES

KW - TEMPERATURE

KW - ANTARCTICA

KW - PHAEOPHYCEAE

KW - SETTLEMENT

KW - MORTALITY

U2 - 10.3389/fmars.2019.00084

DO - 10.3389/fmars.2019.00084

M3 - Article

VL - 6

JO - Frontiers in Marine Science

JF - Frontiers in Marine Science

SN - 2296-7745

M1 - 84

ER -