Statement A:
"A marine biotechnology firm, KelpTech, invested £8.5 million to establish a 500-hectare offshore kelp aquaculture facility. The harvested kelp is processed and sold to manufacture biodegradable packaging, yielding commercial profits for the firm."
Statement B:
"The massive offshore kelp canopy has absorbed high-energy ocean swells, reducing shoreline erosion along the nearby coast by 35%. This has saved local municipal authorities and beachfront homeowners significant costs in coastal defense maintenance. Furthermore, the kelp forest has acted as a critical breeding ground for local marine species, leading to a 30% increase in wild fish stocks harvested by commercial fishing fleets operating outside the aquaculture zone."
With reference to the statements above, explain what is meant by external benefits.