Marine Zoology & Ecosystems: Marine Resources

Marine secondary metabolites

chemical structures produced by marine microorganisms

Marine secondary metabolites: used for

defence

space competition

communication

antifouling

Marine secondary metabolites: produced by

sponges

soft corals

algae

tunicates

Why do sponges invest energy into making complex chemicals

deter predators- lack mobility to defend physically

Sponges as chemical factors: how many products do the produce

produce ~30% of known marine natural products

Sponges are sources of

anti-cancer, antiviral, antibacterial compounds

Sponge product example

Halichondria Okadai

Halichondrin B- anti-cancer molecule

Leads to Eribulin (FDA-approved drug

risk of harvesting sponges

Habitat destruction

Overharvesting

Loss of genetic diversity

Ethical issues

Bryostatins

anti-cancer, memory research

Conotoxins

potent neuroactive peptides

Ecteinascidin-743

anti-tumour drug

Terpenoids

anti-inflammatory compounds

Phlorotannins

antitoxidants, UV-protectants

Macroalgae are

industrial polymers

3 types of algae

Brown, red, green

brown algae

alginates, fucoidans, laminarin

Red algae

agar, carrageenan, phycoerythin

Green algae

ulvans

Structural polysaccharides

biomaterials, biodegradable films

Phenolic compounds

antioxidants used in skincare

Proteins & bioactive peptides

anti-inflammatory, UV protection ingredients

Alginates

gel thickener in pharmaceuticals, foods, biomedical scaffolds

Agar

microbiological culture media

Carrageenan

common in dairy stabilisation, toothpaste viscosity control

Macroalgae does not require

Fertiliser, freshwater, or arable land → strong case for circular bioeconomy

Microalgae

High value compounds

spirulina

high protein (up to 70%), phycocyanin pigment

chlorella

vitamins, antioxidants, detoxifying supplements

dunaliella salina

extreme halophile producing b-carotene

schizochytrium spp

commercial source of DHA omega-3 for vegan supplements

How do microalgae contribute to climate mitigation?

reduce atmospheric CO₂ by fixing carbon during photosynthesis.

Why are microalgae considered highly efficient at CO₂ fixation?

can fix CO₂ up to 50× more efficiently than terrestrial plants

What is bioremediation

uses organisms to remove pollutants

how are microalgae used in bioremediation

microalgae capture CO₂ and remove nutrients like nitrogen and phosphate from wastewater

Which nutrients can microalgae remove from wastewater

Nitrogen and phosphate

How can microalgae production be integrated with aquaculture

By using nutrient-rich aquaculture outflows to support algal growth

How can microalgae be integrated into wastewater treatment systems?

use nutrients in wastewater, improving water quality while growing biomass

How can microalgae help reduce industrial CO₂ emissions

They can use CO₂ from flue gas streams as a carbon source

Macroalgae: case study

Integrated Multi-Trophic Aquaculture adds algae with fish

Macroalgae: case study: salmon farms

seaweed removes nutrients from salmon farms

grows 30/40% faster downstream of salmon cages

Macroalgae: case study: aquaculture

offshore, lots of fish in pens, overcrowding, need fish to feed fish, all get disease, fed antibiotics, lots of faeces

downstream of pens get leftovers

Biomed resources: organism -> compound -> medicine: Horseshoe crab

Horseshoe crab blood -> Limilus Amebocyte Lysate (LAL)

detects bacterial endotoxins in vaccines

saves lives- high mortality in wild populations

Biomed resources: organism -> compound -> medicine: Cone snails

>100 peptides in venom

Ziconotide- non-addictive painkiller, 1000x stronger than morphine

Biomed resources: organism -> compound -> medicine: Tunicates

Ecteinascidin-743

anti cancer drug

Biomed resources: organism -> compound -> medicine: Sea hares & bryzoans

alkaloids & bryostatins

potential Alzheimer's & HIV treatment

Marine microbes: Invisible chemists

Marine bacteria & fungi produce antibiotics, enzymes, pigments

actinomycetes

60% of marine-derived antibiotics

Cyanobacteria

anti-cancer compounds

Marine yeasts

lipid and carotenoid production

Extremophiles

deep-sea, polar microbes

Bioprospecting pipeline

isolate → culture → test → characterise →synthesise

Marine Biotechnology:

organism → gene → enzyme → product

Marine Biotechnology: gene

gene that causes product beyond just extraction- cultivation, fermentation & gene editing

cold-loving bacteria lipases

eco-friendly detergents

Marine Biotechnology: ecological

ecological adaptations

Marine Biotechnology: Biotechnological

biotechnological innovation

Bioprospecting

the ethical search for useful biological compounds

Biopiracy

exploitation of biological/genetic resources without consent/benefit-sharing

Legal frameworks: Nagoya Protocol

fair sharing of genetic resources' benefits

Legal frameworks: High seas treaty

addresses genetic resources in areas beyond national jurisdiction

Ethical imperatives

transparency, consent, data sharing, sustainable sourcing

UN BBNJ Treaty: new 'high seas treaty' aims to regulate

access to marine genetic resources

environmental impact assessments

capacity building for low-income nations

technology transfer

benefit-sharing (monetary and non-monetary)