Starfish, or sea stars, are captivating marine invertebrates belonging to the phylum Echinodermata, a group that also includes sea urchins and sea cucumbers. They are defined by their radial symmetry and the intricate hydraulic system that powers their movement. When exploring tidal pools, the question of whether it is acceptable to pick up and hold these creatures often arises. This article explores the biological reasons behind their fragility and provides guidance on how to observe them responsibly.
The Immediate Answer: Is Handling Allowed?
While a starfish may look durable, marine science universally discourages handling these animals in the wild. The consensus among conservationists and biologists is that the best practice is to observe them without physical contact. This “look, don’t touch” philosophy is rooted in the sea star’s delicate physiology and vulnerability to human interaction.
Physical contact, even if gentle, can cause immediate stress and potential long-term harm. Although specific laws may not prohibit temporary contact, handling them is detrimental to their well-being. Brief observation from a distance is the preferred method for enjoying these creatures.
Understanding Starfish Vulnerability
Starfish possess complex internal mechanisms that make them highly sensitive to removal from water and human touch. They rely on a specialized hydraulic network, the water vascular system, for locomotion, feeding, and respiration. This system uses water pressure to extend and retract hundreds of tiny tube feet, which are easily damaged or detached by handling or slight pressure.
A primary reason for avoiding removal from the water is their unique respiratory system. Starfish do not possess lungs or gills; instead, they breathe through tiny, thin-walled projections on their skin called papulae, or dermal branchiae. These structures facilitate gas exchange by absorbing oxygen from the surrounding water through diffusion and releasing carbon dioxide.
When lifted into the air, these specialized structures cease to function, leading to rapid oxygen deprivation and the buildup of carbon dioxide. Exposure to air for only three to five minutes can cause permanent harm or death in many species. Furthermore, human skin carries bacteria and oils that can disrupt the thin, protective mucus coating, leaving them susceptible to infection.
Safe Interaction Guidelines
If a starfish is encountered in a shallow tide pool, the safest way to interact is to leave it completely undisturbed. The rule of responsible observation is to keep the animal fully submerged in the water at all times. Never lift a starfish partially or fully out of the water for a photograph or closer inspection.
If gentle contact is necessary, such as moving a stranded animal back into deeper water, hands must be thoroughly wet first. Dry hands compromise the animal’s protective mucus layer. Never try to pull or pry a starfish off a surface, as their powerful suction grip means forcible detachment will cause serious injury.
Any brief interaction should be limited to a few seconds to minimize stress. If the starfish is moved, it should be returned to the exact location and orientation it was found in, placed right-side up.