Welcome, I would like to invite all of you to our special
National Marine Sanctuary webinar series.
We're so pleased that you can join us today.
This is a series that is hosted by the NOAA Office of
National Marine Sanctuaries and we find that it's a
great way (Pre-COVID) and during the pandemic to
connect with educators, so formal and informal
educators, students, families and other folks that are
interested in our topics.
To teach them about National Marine Sanctuaries,
help them bring ocean and climate literacy into your
classroom or your home, your facility.
And of course conservation and stewardship of our
special ocean areas.
So we're very pleased that you're all here with us today.
We're excited too that we have (let's go back here) we
have just about 1100 people that have joined us for
today's webinar, so we have hit it out of the park
with interest and in this particular topic about
Hanauma Bay.
So we'll get to that in a minute, but we're hoping that
you'll learn some science from our presenter today
about what has happened at Hanauma Bay without
direct human impact since March of 2020.
And before we get there, I'm going to do a little SLIDO,
which is kind of a new thing we're doing to increase
engagement in our presentations.
And right here, if all goes as planned, we for those of
you that are new to SLIDO, you can join by just going
on your smartphone or on your computer in a
different tab - slido.com and enter 95220.
For those of you that want to try the more advanced
solution, you can pick up your smartphone use the
camera app. to scan this QR code on the right and a
link to the website that will log you into this event for
SLIDO, will be there where you can touch it and you
can join our event.
So again, slido.com, event code 95220 or the camera
app. for the SLIDO QR code.
The first question we're going to ask you today is (for
those of you that are here live with us today) Where
are you located?
So give us the State.
If it's Hawai'i don't put HI, put Hawai'i spell it out.
California, spell it out.
If you're from outside of the United States, we would
love to know what Country you're participating from.
We do get a lot of international interest often times
they join us watching the archive because the timing
isn't ideal for them.
Although we have Slovenia in the house, Nigeria,
Portugal and of course California and Hawai'i are
some of our our states where there's big participation.
So I think it's always fun to kind of see where our
audience is and let our presenter Sarah know where
you guys are coming from.
All right well I'm going to go ahead we've got about
166 of you that are playing SLIDO but I'm going to
switch back to our presentation since we have a
limited time here and we need to get started.
So just a quick introduction to our National Marine
Sanctuary System, each of these blue dots on the
map represent one of these special underwater
treasures or an underwater park that is managed
by NOAA, The National Oceanic and Atmospheric
Administration.
So all of my co-hosts and I are trustees of this system
of underwater parks that encompasses about - well
it's over 600,000 square miles of ocean and
Great Lake treasures.
So as you can see we're going to be diving into the
Hawaiian Islands Humpback Whale National Marine
Sanctuary for today's presentation.
Before we get into that part of the reason why these
special areas are set aside is that we're protecting
the biodiversity, so all the plants and animals that live
in these special underwater parks not only the plants
and animals, we also protect the shipwrecks and the
maritime archaeological heritage and of course the
cultural heritage, as seen here in the Northwestern
Hawaiian Islands.
And these special ocean areas or underwater parks
provide shelter for endangered animals like the
Hawaiian Monk Seal and threatened species like
the Hawaiian Green Sea Turtle, you see in this photo.
And we actually are mandated through the National
Marine Sanctuaries Act to conduct education and
outreach.
We do research and monitoring and all of this is with
the end goal of resource protection, so protecting the
plants and animals and cultural and maritime assets
within these special ocean places and Great Lakes
locations.
And these are these special marine places you can
do lots of recreating there, you can snorkel, scuba
dive, fish, boat, etc. and we're hoping that through
not only this webinar series but some of your personal
connections with the ocean that you might be inspired
to become a volunteer for one of our National Marine
Sanctuaries and if you just get to our
sanctuaries.noaa.gov we have a get involved link that
will give you lots of more details about how to get
involved.
All right, well with that just a quick note all attendees
are in listen only mode.
You're not able to unmute yourselves.
We already have 550 people live today's presentation,
so welcome my name is Claire Fackler, I'm the National
Education Liaison and I'm sitting actually in my kitchen
in Santa Barbara, California.
So I welcome you and I would now like to welcome
our webinar hosts from the Hawaiian Islands
Humpback Whale National Marine Sanctuary and
we've got Allen Tom, who is the Superintendent of
that underwater park joined with Cindy Among-Serrao,
who is the sanctuary advisory council and sanctuary
ocean count coordinator for the Sanctuary there in
the Hawaiian islands and we have Amy Eldredge, who
is the volunteer coordinator also for the Humpback
whale sanctuary in Hawai'i.
So with that Allen go ahead.
So "Aloha" everybody.
Thank you for joining us today all you wonderful people
out there in the dark that I cannot see.
I am the Superintendent of the nation's best national
marine sanctuary, the Hawaiian islands Humpback
Whale National Marine Sanctuary and I am thrilled
that you are all joining us today.
The fact that so many of you have expressed interest
in this topic tells me that not only Hawai'i but you're
interested in about marine protected areas and what
might be happening to them during this time of COVID.
Next slide please.
So you're gonna have to bare with me because I'm
gonna put a plug in for my national marine sanctuary.
And we are located around the main Hawaiian islands
of Hawai'i of course.
And our main office and where you are hearing me
from today, is from the island of Maui but (next slide)
our boundary also extends around the island of Kauai,
where we have a small visitor center and the island
of Oahu.
And I'm not sure if you can see this map or not, but on
the southern shore of Oahu, is part of our sanctuary
boundary which also encompasses, a dot there, the
Hanauma Bay State Underwater Park and that is where
our talk will take place about today.
Next slide.
And so part of what the sanctuary program in Hawai'i
does is, you know, we don't we don't manage the
whales, we manage the people who manage the
whales or at least we try to interact with the people
who deal with the whales.
And so one of the best ways we can do that is to
partner with a variety of organizations to get our
message out to the public.
And what you have here is a tide calendar for the
tides of Hawai'i of course and it is actually free to
the public.
You can download it and it is a collection of
photographs taken by an art contest done through
the Waikiki Aquarium.
So if you are interested, please let us know and we
will send you the link where you can download this.
That's your little gift for calling in today and attending
this webinar.
Next.
And as I said I'm going to put a plug in for my programs.
This month is "Ho'i Kohola" or the "Welcome back of
the humpback whale month", that we have termed and
the whales are actually already back here in Hawai'i.
And we have a number of great talks coming up, not
just this one, but we have talks about how to behave
appropriately out on the water in Hawai'i, when we
have all these different marine mammals and species
here.
That's this Friday.
We have another talk this Friday, by our Research
Coordinator but we also have a great talk at the end
of the month about the cultural significance of
humpback whales.
So I hope that you will join us and continue to be
engaged and enlightened by your Hawaiian Islands
Humpback Whale National Marine Sanctuary.
So I'm going to turn it over to Claire because, as I don't
know if you many of you know this, she's a local girl
who grew up here in Hawai'i and for all of those who
live in Hawai'i, we know of Hanauma Bay, but we're not
sure you do. So we're gonna - I'm gonna turn it over to
Claire to ask the next question.
Yeah so for those that have joined late we're doing a
little bit of SLIDO here slido.com on your smartphone
entering the code 95220 or if you're familiar scan the
QR code and hit the link at the top.
Let's find out how many of you have actually been to
Hanauma Bay on Oahu.
So go ahead and start registering your votes.
All right 170 people have voted, quite a few have been
to Hanauma Bay.
Okay I thought there might be a few not sure right?
Because people get to the Hawaiian islands they have
all these amazing experiences, a decade goes by and
they're like I don't remember where I snorkeled so that
might be some of the not sure's. But it looks like in
general about 60 percent of the audience has been
to Hanauma Bay.
So with that we'll go ahead and let Allen introduce
our presenter Sarah.
Okay well, thank you Claire.
I thought that's interesting two percent aren't really
quite sure if they went to Hanauma Bay but if they
even came to Hawaii at all.
But just kidding.
I am so pleased and honored to to introduce our
speaker - Sarah Severino.
First of all she responded with an enthusiastic "yes,
I will be glad to present on our ONMS Webinar series"
and I don't think she really understood what she was
getting herself into!
But I'm pleased that she agreed to do this.
She is a researcher at the Hawai'i Institute of Marine
Biology.
Sarah holds a Bachelor's from the Hawaii Pacific
University in Marine Biology and she holds a Master's
in Marine Sciences.
But more than that in her young life, she has worked
about, she has worked with or at just about all the
agencies and locations here in Hawai'i, that have
anything to do with reefs, coral reefs or marine biology.
She has interned or worked with the Waikiki Aquarium,
the State Department of Aquatic Resources, Western
Pacific Fisheries Management Council, Oceanic
Institute, she has paid her dues.
And so she is now, as I said, a researcher at the Hawai'i
Institute of Marine Biology and that is the organization -
that is the research institute that is doing this work at
Hanauma Bay.
Sort of doing the transects and doing the research
to find out what's going on there. So without further
ado, I would like to introduce Ms. Sarah Severino.
All right have you received I have you received the
panel at the presenter tools?
Because there's several of you listed here, so I guess
I'll keep going until I find you.
Give me a nod when it -
okay there we go.
Okay there you go found the right Sarah, because I
think some friends and family might be joining in on
your link.
So all right take it away.
Good Morning everyone.
Thank you for the introduction Allen and thanks for
having me here today to talk about the caring capacity
study that the coral reef ecology lab has been performing
at Hanauma bay.
But before we talk about all of this research and there's
a lot, I want to talk about something else.
I want to discuss stress.
I know I'm not the only one here who's had to has
experienced stress but also have has had to manage
and mitigate stress especially during the pandemic.
For me this looks like eating well or getting enough
rest and on the daily, stress can reduce our optimal
functioning but long-term chronic stress can put us
at risk of headaches, weight gain, or things even as
severe as heart disease.
Over time all of these little stressors work together to
degrade our bodies and they make it difficult for us to
even fight off something like a like a cold.
But like I said before we can work together with our
mind and our body to increase our resiliency to stress
by making healthy decisions.
I'm sure you all know this but humans are not the only
animal that experience cumulative chronic stress and
in this way we can closely relate to our coral reefs, they
too are experiencing day-to-day stress that reduces
their fitness such as sedimentation, pollution and breakage.
And the more we let these little stressors keep
happening, the less resilient they'll be to big stressors
like global climate change and these really are the
most prominent stressors in reef degradation.
Today we'll be talking about the steps we're taking to
understand these stressors and determine their
acceptable levels in an attempt to increase resiliency
to the most popular snorkeling reef in Hawai'i,
Hanauma Bay.
One of the drivers we're really familiar with here and
I'm sure many of you in tropical regions are also familiar
with, is tourism.
Hawaii's economy is strongly dependent on tourism
with approximately 85 percent of our visitors
participating in ocean related activities during their stay.
This stimulates our economy, it provides jobs and it also can
foster marine conservation in visitors and in locals.
In recent years some marine businesses in Hawai'i
have even made strides to become more
environmentally conscious and develop
conservation-oriented principles.
But despite being well-intentioned even tours that
have an eco-friendly mind frame can have impacts
on the reef.
Some of the unintended impacts of tourism in Hawai'i
are overuse of an area, incorrect use of an area and
stress on our marine life.
And like I was talking about before, if we continually
place this type of stress on our reefs they have less
of a chance of recovering after severe stressors like
bleaching events, from increased water temperatures.
These events are only increasing in frequency and
severity and we need to take every precaution to
identify and reduce local stressors, to make them
more resilient to global climate change which is
inevitable.
In many ways the management at Hanauma Bay has
been working toward this goal.
Prior to the COVID 19 closure, Hanauma Bay received
approximately 3 000 people or guests per day.
That's around a million annually.
This may seem like a lot but these numbers are
greatly reduced from prior usage of the Bay.
Rewind all the way to 1950 and only approximately
50,000 people annually visited the Bay.
Bring that up to 1967, when Hanauma Bay was coined
a Marine Life Conservation District and around that
same time is when the Division of Aquatic Resources
started monitoring fishes within the Bay, this is one
of the longest term fish data sets in all of the State
of Hawai'i.
Also Dr. Alan Friedlander at the Hawai'i - at
University of Hawai'i has been working with this data
on his own, to look at MPA effectiveness over time.
By the late 1980s, the Bay had over 3 million visitors
annually, around 3.6 million visitors.
That's 13,000 visitors a day.
This was a lot of people.
The crowds were said to stir up sediment, disturb
and trample coral and algae, they dropped trash and
fed the fish.
It was also said that they left a slick of suntan lotion
on the Bay's surface.
Other visitors remembered crowds of people walking
out onto the reef flat to observe and feed fish from a
standing position.
City and County, who managed Hanauma Bay, quickly
realized that this could not be sustainable and they
started to take action.
In the 1990's access to the park was restricted for both
visitors and tour companies and also City and County
asked University of Hawai'i Sea Grant and Friends of
Hanauma Bay to work together and create and
implement an education program that would help
visitors understand how to protect and respect our
reef here at Hanauma Bay and throughout the the
world really.
They provide the proper etiquette for snorkeling and
this is something everyone gets to watch as they
come into the Bay.
In 1998 they affected they put in place a closure on
Tuesdays mostly for maintenance purposes but us
researchers also get to take advantage of this day
and in 1999 they effectively enforced a fish feeding
ban.
The coral reef assessment and monitoring program
began which is the longest term coral monitoring
program in the State, it has sites throughout the
main Hawaiian Islands and has been used for several
long-term data sets.
In addition to this, City and County was mandated to
perform a yearly carrying capacity study in order to
keep managing the Bay and in 1999 is when the first
and only prior carrying capacity study was performed.
But what is a carrying capacity study?
The recreational carrying capacity is termed "the level
of use an area can withstand while providing
sustained quality recreational experiences".
This has four components, the first of which we've
been working on for the past two and a half years.
The biological carrying capacity.
Looking at the ability of resources to withstand
recreational use without unacceptable damage to
ecological components such as water quality, coral
cover or fish diversity.
In future years we will be documenting the other three
types of caring capacity studies: a social carrying
capacity.
This tells us the number and distribution of visitors
that provides minimally acceptable recreational
experiences.
This is difficult because it's very subjective.
For example on an average day, Hanauma sees
3000 visitors.
Let's say on this day a visitor from Montana goes
down to the beach and they may not be satisfied
because the beach feels too crowded.
While on the same day a visitor from New York City
goes down to the beach and they think the beach-
the amount of people on the beach is just fine.
It also has to do with the level of education though.
What is the maximum amount of people that can visit
Hanauma Bay per day and still receive the same
amount of education on reef conservation?
And is this the same for both mainland tourists and
tourists from foreign countries where English is not
their first language?
The third type of carrying capacity is the physical
carrying capacity.
This is not likely to be the limiting factor as it looks
at the amount of space available for each activity
for example the number of people that can physically
fit on the beach at one time with their towels spread
out.
And then lastly we have a facilities carrying capacity.
This documents if the Bay has enough bathrooms,
showers, trash cans for the number of people visiting
the Bay and if they have enough workers to keep all
of these in proper working condition.
The biological carrying capacity study has been
designed to determine acceptable limits of use or
disturbance to marine conserve- to the marine
resources within Hanauma Bay.
Today we'll be talking about what we've done in the
past in the beginning of the carrying capacity study
such as documenting human use, looking at the coral
and fish and also sedimentation.
And then we'll go into what studies we've implemented
during the COVID-19 closure.
All of these studies are performed in an attempt to
link indicators of stress with potential causes so that
action can be initiated before irreversible declines in
health of the Bay occur.
I know many of you said you've been to Hanauma Bay,
but for those of you who haven't, I want to discuss a
little bit about the Bay and which areas we are working.
Here is a picture of the Bay and we've broken the bay
up into five quadrants that we're working in.
You'll notice that the majority of our work is on the
inner reef flat of Hanauma Bay and we'll get to that in
a bit but mostly we're looking at this inner reef flat
because it's shallow enough to have all of these
effects but it also has all the majority of snorkelers
and waders occurring in this area with much fewer
going offshore.
So all of our experiments that I'll go over have been
within these five quadrants of the Bay.
Backdoors, Keyhole, Channel, Witches Brew and
Offshore.
And each of these have two permanent transects within
them that are 5 meters by 15 meters and like I said
all of the experiments will be within these areas.
Including our human counts.
One of our the first things we looked at, over these
sectors was human use.
In order to see if there was a relationship between our
natural resources at Hanauma Bay and the just and
the and human use, we first had to figure out how
many people were using each sector at the Bay.
So we were monitoring spatial and activity patterns
within Hanauma and identifying high and low use
areas for snorkelers.
We did this and other experiments over a period of
two months in June and October of 2018.
The human counts were established using two
different methods.
Both time lapse hourly photos and visual surveys.
Where is everyone snorkeling?
So like I said before the majority all but three percent
of snorkeling takes place in those inner reef flats of
the inner re-flat of Hanauma which is why we are
looking so heavily into the impact of disturbance to the
inner reef flat and less to the outer reef flat.
We also see here that Keyhole sector receives
approximately 50 percent of snorkelers and waders
in the entire Bay and Channel isn't far behind that with
around 40 percent.
Both Witches Brew and Backdoors have very little snorkeling and wading that occur in them.
Now that we have an idea of how many snorkelers are
visiting each sector, we can determine if human use is
a driving factor in things like sedimentation and the
distribution of corals and fishes throughout Hanauma Bay.
Because corals utilize light to produce their energy
source, if the water is more turbid or murky the corals
have less light available to harvest their energy from.
This could also mean that they have to rely on active
feeding strategies to make up for this deficit.
If the coral cannot produce enough food or collect
enough food from the water column, its overall health
will decrease.
We tested the particulates in the water column or the
visual water clarity using what's called a Secci disc
method.
If you're familiar with the Secci disk you'll know that
they're typically used vertically throughout the water
column.
But because our inner reef flat of Hanauma Bay is so
shallow, we performed horizontal Secci disk readings.
We did this over every inshore transect and we also
recorded things like the time of day, cloud cover, wave
height and other influential environmental conditions.
Here's a graph where on the Y-axis here we have visual
Secci distance and on the X-axis we have our different
sectors of the Bay.
We also have two different colors here.
We have dark colors which are days open to the public
and these lighter colors here that are days closed to
the public or those Tuesdays.
We surveyed in both June and October and what we
found here is that visual Secci disc distance or the visual
water clarity increases in every single sector when
you're comparing open days to closed days.
And in fact it increases approximately 30 percent on
days that are closed to the public, however other
factors were contributing to this visibility such as tidal
flux, wind speed and direction wave height and cloud cover.
We first looked at the amount of sediment suspension
in the water column with the Secci disk method.
But what about the sediment and sand that deposits
onto this substrate or the reef flat.
Sedimentation is a threat to coral reefs for two main
reasons.
Sediment falling onto live coral tissue causes them
to expend energy to produce mucus and slough that
sediment off their tissues.
The second reason is that large particles of sand that
have been kicked up by snorkelers, can fall onto the
live coral tissue and in washing back and forth and the
waves can act as a sandpaper scraping their
delicate tissues.
This process is referred to as "sand scour".
Not only does this decrease the overall health of the
coral but it can also leave them susceptible to
infection or disease.
To quantify the amount of sediment falling onto the
reef flat, we placed out sediment traps into each
transect of the Bay.
In these two graphs that we have here the sectors are
outlined in colors referring to the proportions of
swimmers and waders in each area.
So green being very little swimming and wading.
Red being the highest swimming and wading.
The other thing that you'll notice are these dots here.
These dots become larger and darker in color as the
sediment accumulation increases.
A similar pattern was found for sediment
accumulation as was Secci disc water clarity.
Correlations found that as the proportion of visitors
and waders swimming over the transect increase,
the sediment accumulation also increased.
This could happen due to human activity, wave energy
or biomass of animals that degrade substrate, such
as parrotfish who bite at the substrate and excrete sand.
Mean sediment accumulation in October was
significantly higher than mean sediment
accumulation in June.
And this could be the result of higher wave action
and more resuspension of sediment or bringing that
near the traps in October.
Overall there was a significant correlation between
the proportion of visitors in each area and the amount
of sediment accumulation within traps.
Over the same time period as human use counts we
also looked at coral trampling and the way we did this
is that we placed out 70 total coral skeletons along
each of the transects.
We put / we swam along them to document
presence/absence and we also took weekly top-down
photographs to calculate percent loss of the skeleton.
Here is one example.
On the top here you see Keyhole, which is our busiest
sector.
The majority of swimming and waiting fifty percent takes
place in Keyhole and on the bottom here we have an
example coral skeleton from Witches' Brew which
has around two percent swimming and wading.
So this is week one.
We take our photographs and we outline these corals
to look at their top down surface area.
Let's see what they look like after one week of being
in the field.
We see nearly a fifty percent reduction in coral area in
Keyhole, while in Witches Brew, we have the same
amount of area.
This trend continues into week three with a fifty percent
reduction in surface area within the Keyhole corals and
then after that it seems to level off.
On these graphs here we have average percent skeletal
loss per day on the Y-axis and average swim percent
swimmers and waders on the X-axis.
What we can see here is that in both June and October
as swimming and wading increases we also see an
increase in coral trampling.
We wanted to see how these sedimentation and
trampling results relate to the distribution in coral
colonies within transects.
Do these results explain what we're seeing in the
distribution of corals at Hanauma Bay?
And in order to find this out we conducted coral colony
surveys along each of these transects documenting
things like size, coverage, species, growth orientation
partial mortality, new breakage, disease, feeding
scars and rigosity.
On this graph here of average number of corals on the
Y-axis and our sectors on the X, we also have the
average number of corals over time from 2015 all the
way up to 2020.
What we can see here is that the number of colonies
within each of these sectors either remains the same
or increases in some of the sectors and typically this
would be a good sign maybe this could mean that
there was recruitment of new corals or baby corals
coming to the Bay.
But pairing that with our next graph looking at mean
diameter of coral colony on the Y-axis and again sector
on the X-axis with our dates up here.
We see that mean diameter of the colony or the average
size of corals, decreases in almost every sector after
2017 and continues to decrease.
On this graph we're seeing the same information but it's
presented in a different way.
We have mean colony size on the Y or the average size
of the coral and then the number of colonies on the
X here.
If we look at 2015, the trend has a positive slope
showing the number of larger corals was high.
After 2015, all years did have a negative slope and
decreased in mean colony size from year to year, with
2020 experiencing the lowest average colony size.
Over the years in Hanauma the corals have shifted
from being a few very large corals to many small corals
as seen in this photograph here.
From many large corals or a few large corals in 2014
to many smaller corals or broken corals in 2018.
This is the result of partial mortality and this could be
from things like sedimentation and also because we
did experience a major bleaching event in 2015, which
could be responsible for some of the mortality we're
seeing of those larger corals.
After the bleaching event in 2015 we found that
approximately 10 percent of our corals in Hanauma
Bay had suffered mortality but when you compare
that to the rest of the State where many sites suffered
over 50 percent mortality, Hanauma actually got out
pretty well.
The other thing we did here is we looked at observing
the coral form and orientation.
The longer you spend in Hanauma, the more you notice
that the species of coral found on the reef flat are
mounding or encrusting in skeletal form.
You're not seeing any of our more delicate coral
species that are found here in the Hawaiian islands
like the lace coral.
There were no species that exhibit these delicate
skeletal frameworks.
And also the spatial distribution we also see that the
orientation of these corals that are found on vertical
substrate like in this photograph here or in a crevice
that maybe can get by not getting stepped on.
The spatial and distribution, the spatial distribution
and abundance of corals in the shallow reef flat reflect
a historical chronic impact from human use and this
was first noted even back in 2000 during the first
carrying capacity study performed by Dr. Brock and
Alan Kam.
They said that such high visitor use probably dating
back to the 80s, was the result or was this is what
resulted from all that high visitor use.
Next we'll briefly discuss how fish have changed
throughout the years at Hanauma Bay.
In year two we examined the historical fish abundance
in biomass to look at both temporal chain - to examine
temporal changes in fish communities over time.
How that related to things like fish feeding and different
management status.
The comparative analysis was designed to answer
the following questions.
How influential has visitor presence been on the
abundance of fishes over time? And has the abundance or biomass of fishes changed
with the banning of fish feeding.
To look at how the level of visitors at the Bay
was / has impacted the fishes, we performed a
segmented regression using collated data from the
Division of Aquatic Resources long-term fish studies
and Dr. Friedlander with the University of Hawai'i and
the coral reef ecology labs fish abundance surveys of
the inner reef flat.
If you're looking at this segmented regression I have
here you'll see that abundance of fishes is on our
Y-axis with the year on our X-axis.
Our first segment of this regression goes from 1967
to 1990 with an increasing abundance of fishes within
the Bay.
This is likely the result of a fishing ban that was in
place when Hanauma became an MLCD.
The second portion of the segmented regression goes
from 1990 all the way to 2006, with a decreasing
abundance.
This decrease could be the result of lessening visitor
presence and less fish feeding during this time when
more restrictions were placed on the Bay.
Back to that first carrying capacity study performed
in 1999.
Dr. Brock and Alan Kam found that the standing crop
of fishes was significantly greater on days open to the
public than on days closed to the public and they
attributed these changes in fish biomass to fish
associating food with humans after being fed for
30 years.
So with the lessening amount of people coming to the
Bay likely the fish were being fed less even though the
ban on fish feeding did not take place until 1999 but
that could be responsible for a decrease here.
Lastly we have an increase in abundance of fishes
from 2006 to 2018.
This increase is unknown because there isn't any new
management that's been in place since 2006 but this
could be a result in changing fish survey methods, since
survey methods were changed in 2007 represented by
this blue dot here but hopefully the fish are still
increasing in abundance.
Right now we are continuing to take fish abundance
biomass and diversity surveys throughout the Bay.
And now what you're all waiting for: Our COVID 19
closure surveys.
Of the many unforeseen circumstances presented by
the COVID19 pandemic, the reduced human presence
at Hanauma Bay has presented us a unique opportunity
to better understand our impacts on the natural
environment there.
We've continued many of our surveys through the
pandemic and we've also added in several new surveys
such as fish behavior surveys, sedimentation surveys,
coral surveys and abundance of megafauna.
Here we'll talk a little bit about the types of fish
behavior surveys that we've implemented during the
closure that will continue after the closure once
people are invited back to Hanauma Bay.
But why are we worried about fish behavior?
What can this tell us?
Well, fish that experience chronic stress may have
reduced fitness due to decreases in their foraging
rates or not allowing them to eat enough or reach that
high valued food source prior to fleeing from what they
think is a predator, if they think humans are predators.
If the fish shows a decrease in herbivory rates or eating
the algae, when humans return to the Bay this would
suggest that human presence indirectly restricts the
ability of plant-eating fishes to perform one of their
key ecological functions like keeping the reef's algae
in check and providing space on the reef for new coral
recruits.
We're testing this in two ways: by looking at flight
initiation distance, so we're swimming a camera
toward the fish and looking at how far we are from the
fish when it flees.
We'll continue this after the Bay opens up to snorkelers
again to see if the fish flee quicker when more snorkelers
are present, if you increase the amount of predators if
they're thinking of us as predators present.
Do they flee quicker meaning they don't have enough
time to forage.
And to pair with that we've been working with
Dr. Elizabeth Madin at the Hawaii' Institute of Marine
Biology to conduct camera traps for fish foraging
where we place out coral or we place out Go-pros and
we leave them out and they observe the fish when no
one is present and we're counting the foraging rate.
So are these foraging rates less when more snorkelers
are present? We've also implemented two new coral surveys.
The first is adult coral growth surveys: looking at the
corals that remain on the reef flat, how quickly are they
growing and does this growth rate change once we
have visitors back at the Bay?
And also coral recruitment.
Is Hanauma recruitment limited?
Meaning that we're not getting coral larvae or the coral
larvae is not able to settle and recruit to the reef flat?
Or could it be survival limited.
Are the corals recruiting to the reef flat but not able to
grow to be an adult size.
We also have continued our water clarity surveys and
here's a little sneak peek of what's to come in the future
with our results.
But looking here if the visual water clarity distance
changes in the absence of visitors and from preliminary
observations during the closure we see that the water
clarity between open days to the public and the COVID
closure it's actually increased 64 percent, on days where
we're open to the public compared to COVID closure.
Here again we have visual water clarity distance on the
Y-axis are open to the public in the dark. In the gray
closed Tuesdays and the COVID closure in this
light gray.
From these preliminary observations we see not only
an increase on days open to the public to closed
Tuesdays but we also see an increase in water clarity
between closed Tuesdays in 2018 and the COVID
closure now and we're continuing to take more data on
this to make it more robust.
We've also continued our sediment accumulation
surveys looking at whether or not the rates of
sedimentation or sediment deposition change in the
absence of visitors.
And on top of all of that, we've also been documenting
whether we're seeing monk seals or green turtles at the
Bay during our surveys and from preliminary data we're
seeing an increase in activity of monk seals at the Bay
during the COVID closure but it's not statistically
significant due to low sampling numbers.
In summary the water visibility increased an average of
30 percent when Hanauma Bay was closed to the
public and 64 percent while closed during the
COVID19 closure.
The greater the level of snorkelers, the higher the rates
of sedimentation, the higher the rates of breakage and
the lower the coral cover.
Of this coral cover, we're seeing the corals grow in
cracks and crevices and on vertical substrate that's
inaccessible to trampling.
And our coral morphologies or our shapes, our types of
coral within the Bay are conducive to high impact, we
don't have our more delicate skeletal frameworks within
Hanauma Bay.
Looking at our current and historical fish abundance,
biomass and diversity, we did not see any correlation
with the changes in numbers of visitors at this time.
At the end of each year we provide a report on our
findings to City and County.
City and County manage Hanauma Bay and we provide
recommendations to City and County, they are
responsible for implementing recommendations.
Some of the recommendations we've provided are
things like an increase in a park fee to ten dollars per
non-resident.
They're actually going to be increasing this to twelve
dollars per non-resident in the next year.
We've also asked them to disperse users among other
activities to/ like nature hikes, children's programs or
ocean films and to charge a fee for the entire time the
Bay is open to the public.
In this photograph here that I took at 6:15 in the morning,
we already see around 50 people down at the Bay and
the Bay opens at 6:00 but the educational video does
not start showing until 7 which is also when they start
charging a fee.
So many tour operators will try to drop people off prior
to 7, so a large family or a large group does not have to
pay the fee or watch the educational video.
So we're asking that everyone who enters the Bay
watch this this educational video that goes over reef
etiquette.
Some other educational recommendations we've
made: are placing signage along sidewalks and the
beach informing snorkelers of etiquette and safe places
to enter the beach.
So this is saying things like only stand where there's
sand, although it may look like a rock to many people,
all of the rocks in Hanauma Bay do contain living beings
on their surface so standing anywhere where there isn't
sand could be detrimental.
Also informational signs about ongoing research within
the Bay and TV''s in the educational video room with
subtitles in common visiting languages, so everyone
has access to the educational information.
This study could not have been possible without the
funding and help from City and County of Honolulu, all
of the volunteers, Sea Grant Education Program, Friends
of Hanauma Bay and the Division of Aquatic Resources,
as well as the rest of our coral reef ecology lab
members who were instrumental in the collection of
this data set.
Do we have any questions?
Great thank you Sarah.
I think Amy and Cindy will jump on and they have a
few, we've got lots of questions we probably won't get
to all of them but Amy is going to ask a few key
questions here.
Okay yes so please keep sending any of your questions
into the chat box.
There are two here that are similar, so I'm going to try
to combine them but the question was regarding
"How you were identifying the how the coral was damaged.
So how do you know whether it was by a snorkeler or if
it was caused by wave energy or another species might
have broken it up and can you also tell whether or not
let's see that the skeletons were attached with an epoxy
before surveys?"
Those are great questions.
Thank you for asking that.
I didn't have time to go over all of the methodology
but these skeletons were actually attached using a zip
tie through a little hole or "puka" in the reef and then
typically there was epoxy right under them so they
were really stable and the way that we tried to
differentiate between whether the destruction was
from human trampling or fish bites or anything like that.
Is that we also placed these coral skeletons out on the
outer reef flat so that's too deep for humans to trample
and there we saw very little, to no breakage and also in
Witches' Brew where we're seeing very little to no
breakage, we don't have as much human influence but
we still have the same types of fishes that may go
around biting these or the same types of wave action.
Your muted Amy.
Sorry probably one more question and then we'll wrap up.
Great thank you.
One more question here is that they understand the
importance of other measurements of coral colonies
but what does growth orientation tell us about the
health of coral colonies?
It has less to do with the health of coral colonies and
more to do about where corals are able to thrive within
the Bay.
We're not seeing any of these large healthy coral
colonies on the horizontal substrate which is when
you're snorkeling around typically where you're seeing
these large coral colonies that are healthy, so in
Hanauma, our healthy coral colonies are found on that
vertical substrate where it's a lot harder for someone to
kick or step so the fact that all of our larger colonies are
thriving on vertical substrate where hardly any can grow
on the horizontal substrate, is saying that trampling
might be an issue.
Yeah that's a that's a good point.
So as Amy suggested there are many more questions
that have come in through the Go-to-webinar control
panel and we apologize that we won't be able to get to
all of them.
We do want to take the last four minutes here to kind
of wrap up the presentation and go make sure you
know about some of the upcoming events and we did
record today's webinar so it will be made available on
our archive page that's a long government URL.
Don't worry in a follow-up email today you will get that link.
If you have any follow-up questions there's this
sanctuary.education@noaa.gov, email address.
We are promoting this park passport app. that is free
to download from a smartphone because you've just
learned about a specific area in our Hawaiian Islands
Humpback Whale National Marine Sanctuary.
You've earned one virtual visitor badge, so you can go
and download that app. and claim that badge.
I also let you know that as an attendee for today's
webinar presentation, you will receive a certificate of
attendance that looks similar to this, that will count for
one hour of professional development.
At the very end when you close out of the Go-to-webinar
there is a short survey with four questions that would
take you about less than a minute to respond to.
We actually really appreciate getting that information
from you to help evaluate our webinar series program
and then if you are a formal educator or informal
educator and you haven't already done the NOAA
multimedia and distance learning survey, that one might
take 10 to 15 minutes but the link is in the evaluation
following today's presentation.
And then Allen, I'm not sure if you want to promo the
upcoming events?
Sure.
Okay go for it.
I love talking about myself and my program, but I do
want to thank Sarah again for this great talk and I
know that they're working on a report to finalize sort
of what they're seeing at the Bay, it will be out available
to the public probably in another few more months my
understanding.
So there you there will be much more as this progresses
so this year what you're getting is really a snapshot of
what's going on at the Bay and so we do have more
talks coming up.
This Friday if you've ever wondered about why do
humpback whales come back to Hawai'i or what do they
do while they're here?
Well you're going to have to tune in on Friday at noon
Hawai'i time to hear our research coordinator, Dr. Marc
Lammers talk about the research that's going on here in
the Hawaiian islands.
Also next slide please, we have a great talk at the end
of the month by our Sanctuary Advisory Council
chairperson Sol Kahoohalahala, who's going to talk
about the cultural significance of humpback whales
in Hawaii.