patrickbdevaney/mia9 · Datasets at Hugging Face

text stringlengths 0 6.44k
when the algae living on corals escape from the heat, leaving the corals white [61,62].
Other environmental factors (e.g., solar radiation, wind speed and direction, currents,
stratification) additionally deteriorate the resilience of the corals. The recorded coral reef
decline in the Florida Keys is strongly related to the increasing thermal stress due to ocean
warming from climate change [55]. The most lethal coral-disease incident ever recorded on
a contemporary coral reef occurred over southeast Florida during 2014–2015 [63], when very
high occurrence frequencies of MHWs with total durations above 100 days were computed
(Figure 8). Precht et al. [63] associated the coral losses with unusually warm-winter and
spring temperatures followed by an anomalously warm summer, in agreement with our
satellite-derived results that showed high minimum (winter) SST values (Figure 3c) in
2014 and high maximum (summer) values in 2015 (Figure 3b). Besides 2014 and 2015,
Manzello et al. [64] reported one more major bleaching event at Cheeca Rocks, located
between Marathon and Key Largo, in 2011, when increased number of MHWs was also
computed (Figure 8), associated with the increased 99th SST percentile of that year (>30.5 ◦C;
Figure 3b). The peak of MHWs in 1998 (Figure 6a), associated with the high SST (>30.8 ◦C
for 99th percentile; Figure 3b, and >26.5 for mean SST; Figure 3a) of the recent El Nino,
affected the Florida Keys and, in combination to a rise in the growth and reproduction of
microbial pathogens, favored the coral bleaching and mortality in the Florida Keys [65].
The high SST levels of 1998 were also responsible for the formation of MHWs in Biscayne
Bay (Figure 8c), affecting the coral distribution within the enclosed bay [66]. The increasing
number of MHWs observed (e.g., Figure 8e–g) in the Florida Keys between 1996–1999 led
to the reduction of the mean percent of live coral cover in the Florida Keys National Marine
Sanctuary during the same years (approximately 5% reduction; [67]); the bleaching and
cover decline of M. complanata were greatest from 1998 to 1999 that has not recovered
since then. The thermal stress due to the high temperatures of 2015 was also apparent on
seagrass, adding to its mortality in the Florida Bay ecosystem, similarly to another period of
seagrass die-off during 1987–1991 [17], when MHWs were also increased (Figure 6a). Our
findings suggest that the Florida Bay region is a “hot spot” of MHWs, revealing significant
large number of events (>130; Figure 7c) with long durations (>1100 days; Figure 7d) during
the entire study period. Mangrove species along the coastal zone are also controlled by
climate-related factors such as air and soil temperature which correlates with SST due to
tidal inundations [68,69].
MHWs, and especially the recorded increasing trends of their event number and
duration, can also affect the well-being of coastal communities. The results are significant political and socio-economic ramifications, such as effects on recreation and tourism
(e.g., impacts on coral reefs), aquaculture or important fishery species [13]. The biotic
and habitat loss of corals due to ocean warming may result in severe economic and social losses [70]. Birkeland [71] estimated that Florida’s reefs produce approximately USD
1.6 billion annually in tourism value. Chen et al. [72], based on different RCP climate
scenarios during the 21st century, estimated that the future global coral reef recreational
and tourism value loss may range from USD 1.88 to USD 12.02 billion annually. Changing conditions can also help invasive alien species to spread, which can be devastating
for marine food webs as reported by the International Union for Conservation of Nature
(IUCN; https://www.iucn.org/resources/issues-brief/marine-heatwaves, accessed on
1 September 2022). Protracted high ocean temperatures and the associated MHWs may
Water 2022, 14, 3840 24 of 28
also affect several economically important species like lobster [73] and snow crab [74].
Moreover, the mortality and destruction of those species that contribute to the coastal
defense against erosion and flooding, indirectly affect coastal communities’ socioeconomic
conditions. Coral reefs [75] and mangroves [76] may reduce the wave energy that reaches
the shore and minimize the impact of hurricanes and the associated storm surge, protecting
coastal economic activity [77,78]. The incoming waves can be reduced between 50% to
100% using mangroves of 500 m width [79] and up to 97% over coral reefs [80], maintaining
the sandy beaches [81].
The severe MHW events recorded posterior to 2015, and especially in 2019 and 2020
(Figure 6), at all coastal areas (Figure 8) might also have further affected the natural and
human system of South Florida, requiring more interdisciplinary studies to estimate the
impact of the strong increasing trends of the ocean temperature and the associated MHW
formations. It is essential to develop a better understanding of how the MHWs impact
these tropical ecosystems and the people that rely on these ecosystems for their livelihood.
Urban planning for sustainable development in South Florida’s coastal cities must take into
account MHW trends.
5. Conclusions
The formation of Marine Heat Waves (MHWs) over natural and urban coastal environment of South Florida, related to the increasing trends of Sea Surface Temperature
(SST) at the adjacent ocean waters, has been investigated with the use of high-resolution
satellite-derived SST data during 1982–2021. We showed that the SST daily fields covering the 40-year period are suitable to estimate the temperature distribution over the
topographically complicated South Florida coastal region and to examine the formation of
MHW events.
The interannual positive trend of the MHWs is 0.75 events/decade with 7.4 days/decade
duration increase and is associated with the general increasing SST trend over the entire region (0.19 ◦C/decade), following the respective atmospheric temperature (0.21 ◦C/decade)
and the heat flux (~5000 J/m2/decade) increases. The period between 2013–2021 revealed
the highest SST levels, during both winter and summer, while the increasing trends of the
previous period were mainly associated with summer extremes. Although the majority
of the MHWs of South Florida are “moderate” events, based on the Hobday et al. (2018)
categorization, in the years after 2015, “severe” MHWs were also formed. Specifically,
the seven most recent years (2015–2021) were characterized by the strongest formation
of MHWs and strong peaks in 2015, 2019 and 2020 with more than 8 events/year and
approximately 70 to 110 days/year duration in total. During the last decade, the annual
variance was also smaller than the previous period confirming the general warming of the
ocean throughout all seasons (both winter and summer months).
The south WFS and Florida Bay showed the highest number of events during the
40-year period, but significantly long MHWs also occurred at the northern parts of WFS.
The interannual trends of MHWs were though weak over coastal WFS, with small increasing
slopes at the coastal areas of Tampa and Fort Myers. The Dry Tortugas and Florida Keys,
especially along the Straits of Florida (southern coasts) revealed very strong increasing
trends. Miami Beach is also characterized by strong interannual trends (1.1 events/decade
and 10 days/decade) compared to the enclosed basin of Biscayne Bay. Although the
atmospheric conditions mainly affected the formation of MHWs over all coastal regions,
the eastern Florida coasts and especially the most exposed (e.g., Miami Beach) are also
controlled by ocean dynamics, related to the warm Florida Current (FC). The evolution of
the FC close to the eastern coasts is a pre-condition of MHW formation, while its offshore
shift away from the coast results to colder coastal waters, unfavorable for MWH formation.
The colder waters have been detected in the central Western Florida Shelf (WFS) between
the months of January to March, while the Eastern Florida Shelf (EFS), south of Florida Keys,
and the southwestern WFS include the warmest coastal areas with the highest interannual
increasing trends.
Water 2022, 14, 3840 25 of 28
Several disastrous events on the biotic environment of South Florida are related to
unusual temperature extremes and coincide with the peaks of MHWs. Coral Bleaching is
strongly related to MHW events over the Florida Reef Tract. More investigation of the effect
of ocean physical properties and their variability on the biochemical characteristics and
the resilience of species, sensitive to heat stress, is essential. The indirect but strong impact
of MHWs, and especially the increasing trends detected during the last decades, on the

when the algae living on corals escape from the heat, leaving the corals white [61,62].

Other environmental factors (e.g., solar radiation, wind speed and direction, currents,

stratification) additionally deteriorate the resilience of the corals. The recorded coral reef

decline in the Florida Keys is strongly related to the increasing thermal stress due to ocean

warming from climate change [55]. The most lethal coral-disease incident ever recorded on

a contemporary coral reef occurred over southeast Florida during 2014–2015 [63], when very

high occurrence frequencies of MHWs with total durations above 100 days were computed

(Figure 8). Precht et al. [63] associated the coral losses with unusually warm-winter and

spring temperatures followed by an anomalously warm summer, in agreement with our

satellite-derived results that showed high minimum (winter) SST values (Figure 3c) in

2014 and high maximum (summer) values in 2015 (Figure 3b). Besides 2014 and 2015,

Manzello et al. [64] reported one more major bleaching event at Cheeca Rocks, located

between Marathon and Key Largo, in 2011, when increased number of MHWs was also

computed (Figure 8), associated with the increased 99th SST percentile of that year (>30.5 ◦C;

Figure 3b). The peak of MHWs in 1998 (Figure 6a), associated with the high SST (>30.8 ◦C

for 99th percentile; Figure 3b, and >26.5 for mean SST; Figure 3a) of the recent El Nino,

affected the Florida Keys and, in combination to a rise in the growth and reproduction of

microbial pathogens, favored the coral bleaching and mortality in the Florida Keys [65].

The high SST levels of 1998 were also responsible for the formation of MHWs in Biscayne

Bay (Figure 8c), affecting the coral distribution within the enclosed bay [66]. The increasing

number of MHWs observed (e.g., Figure 8e–g) in the Florida Keys between 1996–1999 led

to the reduction of the mean percent of live coral cover in the Florida Keys National Marine

Sanctuary during the same years (approximately 5% reduction; [67]); the bleaching and

cover decline of M. complanata were greatest from 1998 to 1999 that has not recovered

since then. The thermal stress due to the high temperatures of 2015 was also apparent on

seagrass, adding to its mortality in the Florida Bay ecosystem, similarly to another period of

seagrass die-off during 1987–1991 [17], when MHWs were also increased (Figure 6a). Our

findings suggest that the Florida Bay region is a “hot spot” of MHWs, revealing significant

large number of events (>130; Figure 7c) with long durations (>1100 days; Figure 7d) during

the entire study period. Mangrove species along the coastal zone are also controlled by

climate-related factors such as air and soil temperature which correlates with SST due to

tidal inundations [68,69].

MHWs, and especially the recorded increasing trends of their event number and

duration, can also affect the well-being of coastal communities. The results are significant political and socio-economic ramifications, such as effects on recreation and tourism

(e.g., impacts on coral reefs), aquaculture or important fishery species [13]. The biotic

and habitat loss of corals due to ocean warming may result in severe economic and social losses [70]. Birkeland [71] estimated that Florida’s reefs produce approximately USD

1.6 billion annually in tourism value. Chen et al. [72], based on different RCP climate

scenarios during the 21st century, estimated that the future global coral reef recreational

and tourism value loss may range from USD 1.88 to USD 12.02 billion annually. Changing conditions can also help invasive alien species to spread, which can be devastating

for marine food webs as reported by the International Union for Conservation of Nature

(IUCN; https://www.iucn.org/resources/issues-brief/marine-heatwaves, accessed on

1 September 2022). Protracted high ocean temperatures and the associated MHWs may

Water 2022, 14, 3840 24 of 28

also affect several economically important species like lobster [73] and snow crab [74].

Moreover, the mortality and destruction of those species that contribute to the coastal

defense against erosion and flooding, indirectly affect coastal communities’ socioeconomic

conditions. Coral reefs [75] and mangroves [76] may reduce the wave energy that reaches

the shore and minimize the impact of hurricanes and the associated storm surge, protecting

coastal economic activity [77,78]. The incoming waves can be reduced between 50% to

100% using mangroves of 500 m width [79] and up to 97% over coral reefs [80], maintaining

the sandy beaches [81].

The severe MHW events recorded posterior to 2015, and especially in 2019 and 2020

(Figure 6), at all coastal areas (Figure 8) might also have further affected the natural and

human system of South Florida, requiring more interdisciplinary studies to estimate the

impact of the strong increasing trends of the ocean temperature and the associated MHW

formations. It is essential to develop a better understanding of how the MHWs impact

these tropical ecosystems and the people that rely on these ecosystems for their livelihood.

Urban planning for sustainable development in South Florida’s coastal cities must take into

account MHW trends.

5. Conclusions

The formation of Marine Heat Waves (MHWs) over natural and urban coastal environment of South Florida, related to the increasing trends of Sea Surface Temperature

(SST) at the adjacent ocean waters, has been investigated with the use of high-resolution

satellite-derived SST data during 1982–2021. We showed that the SST daily fields covering the 40-year period are suitable to estimate the temperature distribution over the

topographically complicated South Florida coastal region and to examine the formation of

MHW events.

The interannual positive trend of the MHWs is 0.75 events/decade with 7.4 days/decade

duration increase and is associated with the general increasing SST trend over the entire region (0.19 ◦C/decade), following the respective atmospheric temperature (0.21 ◦C/decade)

and the heat flux (~5000 J/m2/decade) increases. The period between 2013–2021 revealed

the highest SST levels, during both winter and summer, while the increasing trends of the

previous period were mainly associated with summer extremes. Although the majority

of the MHWs of South Florida are “moderate” events, based on the Hobday et al. (2018)

categorization, in the years after 2015, “severe” MHWs were also formed. Specifically,

the seven most recent years (2015–2021) were characterized by the strongest formation

of MHWs and strong peaks in 2015, 2019 and 2020 with more than 8 events/year and

approximately 70 to 110 days/year duration in total. During the last decade, the annual

variance was also smaller than the previous period confirming the general warming of the

ocean throughout all seasons (both winter and summer months).

The south WFS and Florida Bay showed the highest number of events during the

40-year period, but significantly long MHWs also occurred at the northern parts of WFS.

The interannual trends of MHWs were though weak over coastal WFS, with small increasing

slopes at the coastal areas of Tampa and Fort Myers. The Dry Tortugas and Florida Keys,

especially along the Straits of Florida (southern coasts) revealed very strong increasing

trends. Miami Beach is also characterized by strong interannual trends (1.1 events/decade

and 10 days/decade) compared to the enclosed basin of Biscayne Bay. Although the

atmospheric conditions mainly affected the formation of MHWs over all coastal regions,

the eastern Florida coasts and especially the most exposed (e.g., Miami Beach) are also

controlled by ocean dynamics, related to the warm Florida Current (FC). The evolution of

the FC close to the eastern coasts is a pre-condition of MHW formation, while its offshore

shift away from the coast results to colder coastal waters, unfavorable for MWH formation.

The colder waters have been detected in the central Western Florida Shelf (WFS) between

the months of January to March, while the Eastern Florida Shelf (EFS), south of Florida Keys,

and the southwestern WFS include the warmest coastal areas with the highest interannual

increasing trends.

Water 2022, 14, 3840 25 of 28

Several disastrous events on the biotic environment of South Florida are related to

unusual temperature extremes and coincide with the peaks of MHWs. Coral Bleaching is

strongly related to MHW events over the Florida Reef Tract. More investigation of the effect

of ocean physical properties and their variability on the biochemical characteristics and

the resilience of species, sensitive to heat stress, is essential. The indirect but strong impact

of MHWs, and especially the increasing trends detected during the last decades, on the