Bumphead Parrotfish Research

Summary

Richard Hamilton from the Nature Conservancy discusses the importance of the giant parrotfish, a keystone species in coral reef ecosystems, particularly in the Solomon Islands and Papua New Guinea. These fish, known for creating sand and clearing space for new coral, are threatened by overfishing and habitat destruction due to logging. Hamilton's research reveals that protecting nursery habitats and implementing sustainable land practices are crucial for the survival of this species and the health of marine ecosystems.

Takeaways

• 🐠 Richard Hamilton works for The Nature Conservancy, focusing on coral reef fisheries in the Solomon Islands and Papua New Guinea.
• 🌊 The giant parrotfish, also known as the bumphead parrotfish, is a keystone species crucial for the health of coral reef ecosystems.
• 📏 These parrotfish can grow over one-and-a-half meters in length and weigh over 50 kilograms, playing a significant role in coral reef maintenance.
• 🥖 They are called 'bio rotators' because they consume about 5,000 kilos of coral annually and produce a lot of sand, aiding in coral settlement.
• 🔍 The species is vulnerable due to overfishing, long lifespan, and the tendency to sleep in groups, making them easy targets for spearfishers.
• 🌙 The bumphead parrotfish spawn throughout the year, with a strong lunar pattern, particularly before the new moon.
• 🌱 The juveniles of this species are highly dependent on specific nursery habitats, which are often high coral cover areas in lagoons.
• 🌲 Logging and poor land-based practices are major threats to these nursery habitats, leading to a decline in the species' population.
• 📉 The destruction of nursery habitats due to logging has a direct impact on the health of the fishery and the overall marine ecosystem.
• 🌳 To preserve the bumphead parrotfish and maintain healthy fisheries, sustainable land-based practices and the protection of nursery habitats are essential.

Q & A

What is Richard Hamilton's area of specialty?

Richard Hamilton specializes in coral reef fisheries.

Which organization does Richard Hamilton work for?

Richard Hamilton works for The Nature Conservancy, a non-profit environmental organization.

In which regions is Richard Hamilton's fieldwork primarily conducted?

Richard Hamilton's fieldwork is mainly conducted in the Solomon Islands and Papua New Guinea.

What is the significance of the giant parrotfish in coral reef ecosystems?

The giant parrotfish, also known as the bumphead parrotfish, is a keystone species in healthy coral reef systems, acting as a bioeroder that produces sand and clears areas for new coral settlement.

How much coral does a large adult parrotfish consume annually?

A large adult parrotfish consumes about 5,000 kilos of coral each year.

Why is the bumphead parrotfish vulnerable to overfishing?

The bumphead parrotfish is vulnerable to overfishing due to its long lifespan, large size, and behavior of sleeping in large groups, which makes it an easy target for spearfishing.

What is the current conservation status of the bumphead parrotfish according to the IUCN Red List?

The bumphead parrotfish is listed as vulnerable on the IUCN Red List.

What is the primary focus of the project Richard Hamilton has been running in the Solomon Islands?

The primary focus of the project is the bumphead parrotfish fishery in the Kea district of Isabel province, Solomon Islands.

What is the role of lagoons in the life cycle of the bumphead parrotfish?

Lagoons play a critical role as nursery stages for the bumphead parrotfish, providing a habitat for juveniles before they move to the outer reefs.

How does the bumphead parrotfish reproduce and what is the lunar component of their spawning?

The bumphead parrotfish reproduces by spawning on the outer reefs, releasing eggs and sperm into the water for fertilization. Their spawning has a strong lunar component, occurring just prior to the new moon.

What impact has logging had on the nursery habitats of the bumphead parrotfish?

Logging has led to the destruction of nursery habitats due to increased sedimentation from the removal of trees and soil erosion, which has a detrimental effect on the juvenile bumphead parrotfish and overall fishery health.

What is the importance of sustainable land-based practices in preserving the bumphead parrotfish fishery?

Sustainable land-based practices are crucial for preserving the fishery as they help maintain the health of the nursery habitats and prevent the loss of juvenile fish, which are essential for the replenishment of adult fish populations.

Outlines

00:00

🐟 Conservation of Bumphead Parrotfish

Richard Hamilton, representing the Nature Conservancy, discusses his work on coral reef fisheries, particularly focusing on the giant parrotfish, also known as the bumphead parrotfish. This species is significant for its role in creating sand and clearing areas for new coral settlement, and it is crucial for the health of marine ecosystems. Despite being overfished and listed as vulnerable on the IUCN Red List, the bumphead parrotfish is still abundant in the Solomon Islands due to the region's extensive lagoons and outer reefs that support its life cycle. The species matures at around seven to eight years, spawns year-round with a lunar pattern, and has a long life span of about 40 years. The research conducted by Hamilton and his team aims to protect this keystone species by working with local fisheries and fishermen.

05:01

🌳 Impact of Land Practices on Marine Ecosystems

The second paragraph reveals the unexpected findings of the research on the bumphead parrotfish. While overfishing was initially suspected as the primary threat, it was discovered that land-based activities, particularly logging, have a severe impact on the fish's juvenile habitats. Logging leads to increased sedimentation in lagoons, which destroys the nursery areas essential for the survival of juvenile fish. This realization has prompted a shift in the approach to fisheries management, emphasizing the need to control land practices to protect marine ecosystems. The stark contrast between logged and unlogged areas, as observed in the research, underscores the importance of preserving these habitats for the long-term health of fisheries. The message is clear: sustainable land practices are as crucial as marine conservation efforts to ensure the survival of species like the bumphead parrotfish.

Keywords

💡Coral Reef Fisheries

Coral reef fisheries refer to the ecosystem and human activities surrounding the fishing of marine species that inhabit coral reefs. These are biologically diverse and productive ecosystems that are crucial for both biodiversity and human livelihoods. In the video, Richard Hamilton discusses his work with the Nature Conservancy, focusing on coral reef fisheries, particularly in the Solomon Islands and Papua New Guinea, emphasizing the importance of these ecosystems for both the environment and local communities.

💡Giant Parrotfish

The giant parrotfish, also known as the bumphead parrotfish, is a large species of parrotfish that plays a significant role in coral reef ecosystems. It is described as a keystone species due to its role in maintaining the health of the reef by eating coral and producing sand, which aids in the settlement of new coral. The video highlights the giant parrotfish's importance and the challenges it faces due to overfishing and habitat destruction.

💡Keystone Species

A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. In the video, the giant parrotfish is identified as a keystone species because it influences the structure of the entire coral reef ecosystem. Its role in producing sand and clearing areas for new coral settlement is crucial for the health and diversity of the reef.

💡Overfishing

Overfishing is the practice of catching fish at a rate that is not sustainable, leading to a decrease in fish populations. The video discusses how overfishing has contributed to the decline in numbers of the giant parrotfish, which is particularly vulnerable due to its behavior of sleeping in large groups, making it an easy target for spearfishers.

💡IUCN Red List

The IUCN Red List is a critical inventory of the global conservation status of species, providing a system for classifying species according to their risk of extinction. In the script, it is mentioned that the giant parrotfish was listed as 'vulnerable' on the IUCN Red List, indicating that it is facing a high risk of extinction in the wild.

💡Nursery Areas

Nursery areas are specific locations within an ecosystem where young organisms, such as fish larvae, find shelter and abundant food sources, which are essential for their survival and growth. The video emphasizes the importance of lagoon and fringing reef areas as nurseries for juvenile fish, including the giant parrotfish, and how these areas are crucial for the replenishment of adult fish populations.

💡Spawning

Spawning in the context of the video refers to the reproductive behavior of fish, where they release eggs and sperm into the water to fertilize and develop into larvae. The giant parrotfish is described to have a year-round spawning behavior with a strong lunar component, particularly occurring just prior to the new moon. This knowledge is important for understanding the life cycle and reproductive patterns of the species.

💡Sedimentation

Sedimentation in the video refers to the process by which soil and other particles are deposited in the water, often as a result of land-based activities like logging. Excessive sedimentation can smother coral reefs and destroy nursery habitats, which is a significant threat to the survival of juvenile fish like the giant parrotfish. The video illustrates how logging practices can lead to increased sedimentation, negatively impacting the health of coral reef ecosystems.

💡Land-Based Practices

Land-based practices are human activities that occur on land and can have direct or indirect impacts on marine ecosystems. The video discusses how logging and other land-based activities can lead to increased sedimentation and destruction of nursery habitats, which in turn affects the health and sustainability of coral reef fisheries. It emphasizes the need for sustainable land management to protect marine resources.

💡Ridge to Reefs Approach

The ridge to reefs approach is a holistic management strategy that considers the interconnectedness of terrestrial, freshwater, and marine ecosystems. The video highlights the importance of this approach in managing fisheries and preserving coral reef health, as it recognizes that the health of marine ecosystems is influenced by what happens on land. By managing both land and sea resources sustainably, the approach aims to maintain the natural balance and productivity of these ecosystems.

Highlights

Richard Hamilton works for the Nature Conservancy, focusing on coral reef fisheries.

His fieldwork is primarily conducted in the Solomon Islands and Papua New Guinea.

Hamilton's recent work centers on the giant parrotfish, also known as the bumphead parrotfish.

The bumphead parrotfish is a keystone species, crucial for healthy reef systems.

These parrotfish can reach over one-and-a-half meters in length and weigh over 50 kilograms.

They act as bio-rotor, producing sand and consuming large amounts of coral.

An adult can eat approximately 5,000 kilos of coral annually.

The species has been overfished globally, with numbers rapidly declining.

They are vulnerable due to their long lifespan, large size, and group sleeping behavior.

The bumphead parrotfish was listed as vulnerable on the IUCN Red List.

A large project in the Kea district of Isabel province focuses on the bumphead parrotfish fishery.

The Kea district is one of the richest areas globally for bumphead parrotfish.

The life cycle of these fish includes long lives, reaching up to 40 years, and maturing around seven to eight years old.

Spawning occurs throughout the year, with a strong lunar component, particularly before the new moon.

Juvenile habitats are critical and are more limited than previously thought.

The Solomon Islands have historically been rich in bumphead parrotfish, forming an important fishery.

The fishery's health was better than expected, but the impact of land-based practices was a significant surprise.

Logging and poor land practices were found to heavily impact juvenile habitats and fish populations.

A ridge-to-reef approach is necessary for managing fisheries and preserving habitats.

Sustainable land practices are essential for maintaining healthy fisheries and preserving marine resources.

Transcripts

my name is Richard Hamilton I work for

the Nature Conservancy which is a

non-for-profit environmental

organization my area specialty is coral

reef fisheries and most of my fieldwork

is conducted in the Solomon Islands and

in Papua New Guinea the last couple of

years we've been working on a big

parrotfish it's the giant parrotfish

know and commonly is the bumphead

parrotfish it's the giant of all

parrotfish it reaches over

one-and-a-half metres in length and

probably quite well over 50 kilograms

and it's it's a keystone species it's

very important in healthy systems it's

the main bio rotor which means that it

produces a lot of sand and eats a lot of

coral a large adult parrot fish will eat

about 5,000 kilos of coral every year so

they produce a great deal of sand and

they also clear out areas which allows

for the new settlement of new coral

recruits it's been overfished in a lot

of areas in the world it's got a wide

geographical distribution but it's

numbers are going down very rapidly for

all the normal reasons it's long-lived

that's naturally rare because of the

size and it has this really quite

unfortunate behavior of sleeping in

large groups the same schools which it

naturally forms during the day and that

makes it very very vulnerable to tonight

spearfishing and recently it was listed

on the IUCN Red List as vulnerable

for the last two years we've been

running a fairly large project here with

national and provincial fisheries and

also to local fishermen and the Kea

district of Isabel province Solomon

Islands and we've been focusing

exclusively on the bumphead parrotfish

fishery care district of Isabel province

probably is still one of the most rich

areas in the world for bumphead

parrotfish and that's partly because

they have both a very large area of

lagoons which is critical for the

nursery stages of that species and also

very extensive outer reefs which provide

the food for the adults the life cycle

of these these fishes you know they're

long lived they're living to about 40

years old they mature at about seven or

eight years of age at which these are a

big fish they're about 60 60 centimetres

in length the adults spawn on the outer

reefs and we found out for the research

that the spawning is throughout the year

but it has a very strong lunar component

the spawning just prior to the new moon

they spawn within their normal school so

often in the early morning there'll be a

school of 30 or 40 parrotfish and they

rush up and like a lot of fish they

release the eggs and the and the sperm

into the water so it's fertilization

within the water itself and then these

fertilized eggs will actually float

somewhere out there and then the great

out knowing for about and four to five

weeks we think and develop into little

larvae when they've reached you know

four or five weeks and age that's when

they recruit back into the lagoon all

areas and try and settle in some

suitable habitats so after about four or

five weeks they recruit back in full of

goons at a very small size I mean just

this week we've been surveying them and

we've been seeing little bumphead

parrotfish which you know no more than

two centimetres in length and and one of

the things we found out in this research

is that the the recruitment habitat of

these species is extremely limited it's

much more limited than we used to think

they're only recruiting into these

really really high coral cover in a

lagoon or fringing reefs so environments

that most people don't look in for

obvious reasons you know the dirty you

get crocodiles in there they're not

they're not sort of spectacular dive

sites or anything like that but really

really rich in all sorts of juvenile

species of fish

and and that the bumphead parrotfish

unlike a lot of species seems to almost

exclusively only recruit into that

habitat so to some extent that would

explain why you have so many bumphead

parrotfish and also fish in general here

and in the Kerr district that's just

these nurseries are just the factory

data stream churning over these some new

new fish into the system the Solomons is

pretty pretty rich in bumphead

parrotfish historically it's probably

one of the areas in the world where

there is still quite large numbers of

bumphead parrotfish it's formed an

important fishery in the Solomons or

part of a subsistence fishery for you

know hundreds thousands of years but

probably in the last forty or fifty

years it's become more and more

commercialized and that relates to the

ease of capture which is night spear

fishermen now being able to find large

numbers at night and it also relates to

the fact that just the large volume of

returned most most coral reef fish are

small but with bumphead parrotfish

approaching 40 or even 50 kilos per

individual and sleep in two given groups

it's not unusual in areas where they're

still fairly healthy to see catches

which exceeds 600 kilos in a night and

it's it's it's pretty important for a

local economy it probably puts about

quarter of a million Solomon dollars

into the local economy each year I guess

when we when we started when I started

this research I expected to find a

fishery which was under pretty heavy

fishing pressure and probably not all

that healthy a couple of things that

surprised me to really first the fishery

is healthier than I expected but the

real big surprise and the really

unexpected outcome of this research has

been that we had no concept before this

of how important these inner Lagoon or

nursery areas were for fish fish and how

heavily impact that they are by land

based practices so in this in this care

district where there's been a lot of

logging in the areas which are logged

all the nursery habitat is gone it's

just it's just destroyed the

sedimentation happens from logging I

mean you you you cut down the trees you

pull the trees the logs down to the

logging ponds and all of a sudden every

time it rains you have all this red clay

mud rushing into a

Lagoon or system which already sustains

a lot of sedimentation but it's kind of

held in check by these extensive

mangrove systems but they right at their

carrying capacity and if you take off

the top soil and then you open up an

avenue for all that soil to run into the

sieve and it just totally swamps the

whole system we've been diving in some

of these areas where there's logging and

it's it's not that Pleasant you know

there's just there's silk this high over

everything and even the big massive

balmy peratis which are probably the

hardiest : if they're starting to die as

well died was suffering from disease as

all its it's in a poor poor state we

didn't really think about the logging

issue when we started this research I

certainly didn't I mean I've seen and

read about declines in bumphead

parrotfish in a lot of places in the

Pacific and it's interesting because

myself and everyone else who has ever

worked on bumphead parrotfish has always

attributed those declines exclusively to

fishing pressure and while there's no

doubt that they are vulnerable for

fishing pressure I think the really

surprising thing well the unexpected

thing that we discovered in this

research was that it's these juvenile

habitats the destruction of those

habitats through poor land-based

practices is probably largely what's

driving the demise of that species in

many places that was a big surprise and

and for me it really changed the way I

thought about how to manage these

fisheries you really do need a rigid

Teresa proach you need to look at

controlling land-based practices if you

want to have healthy fisheries so in the

last two weeks I've done a survey

exclusively in the nurseries and we've

compared that logged area with this

other Island which are on now burrow fur

which is the last large unlogged island

in the whole of isabel province and it's

there's been a lot of pressure there's

been nine timber rights the log this

island over the last 20 years the last

one was just defeated its April and we

wrote and campaigned against not long in

that area based on its importance for

the fisheries but it's it's it's black

and white you know we did we did 20

surveys or 100 transects in the logged

area and we didn't see one juvenile

bumphead parrotfish

and all the reefs were dead or in a very

very poor state a lot of siltation and

then we've done the same thing here in

the last week and it's just like it's a

completely different world this there's

baby bump head parrotfish everywhere so

I would say I probably got it wrong

about ten years ago when I figured that

uninvited parish in the Western Province

was all over fishing it was almost

definitely a combination of destruction

of the nursery areas from logging poor

land based practices and and also heavy

fishing on the adult stocks they're

really important take-home messages that

in these areas where you have these

incredibly rich marine areas and the

rich in part or a very large part

because these very productive nursery

areas for a whole range of of juvenile

fish they already they're already under

pretty heavy natural sediment loads if

you log those islands you'll lose your

fishery the lagoon systems which support

that the high coral reef systems which

support those juveniles they'll

disappear they'll be the first ones to

go and in 10 or 15 years you won't have

any adult fish on the outer reef fever

so it's it's a strong message it's a

ridge to reefs approach it's one we're

trying to promote where as you know

stuff flows downhill you can't we could

we could do all the management we liked

on the outer reef we could set up MPAs

we could put in a closed season when

they're spawning but if logging goes hit

on this island will still lose well

still will still lose that resource

it'll be it'll be gone in 20 years time

because there will be no new fish coming

coming back in to change one's being

taken out so if you're interested in

preserving your fisheries and in having

healthy fisheries you have to also look

at good sustainable land based practices

and areas like this and this is probably

the richest area for fish anywhere in

the Solomon Islands it's remarkable just

don't log it you know just don't or

you'll you'll lose your land resources

and you'll lose your fish as well

you