Case study: Octopus exhibits

Case study: Octopus exhibits

Octopuses are carnivorous, marine animals considered the most intelligent invertebrate. They have a well-developed nervous system and a complex brain, which is relatively larger than the brains of some fishes and reptiles.

Octopuses have numerous sense organs which rival those found in vertebrates in their complexity, including excellent eyesight and sense of touch. Like other animals, octopuses have temperaments that vary between individuals. They learn mazes, distinguish between shapes and patterns in classical conditioning, use landmark navigation whilst foraging, use tools, and play. Despite this, they are afforded no protection whatsoever under the Animal Welfare Act 2006.

In the wild, Octopuses eat small scallops, snails, fish, turtles, particularly crustaceans and molluscs, and walk on the sea floor by a fast, relaxed scrambling or a slower exploratory walking, using their arms and suckers. They swim by propelling themselves backwards by spewing a jet of water from a funnel (or siphon), which is also used to pump water into the gills to obtain oxygen.

swimNatural behaviours in octopuses include home modification and complex tool use. They are capable of long-term potentiation, facilitating the development of long-term memory. This potential for the development of learning and memory might support suggestions that there is a need for larger, more stimulating enclosures if housed in captivity.

Four species of Octopuses are housed at Sea Life aquariums – Mud octopus (Octopus bimaculoides), Mimic octopus (Thaumoctopus mimicus), Giant pacific octopus and Common octopus – all housed in extremely small, barren tanks in areas titled ‘Octopuses Gardens’, or ‘Weird and Wonderful’. The majority of Octopuses live alone, which Sea Life claims is to prevent aggression. With a large enough area for the animals to retreat from each other however, this would not be problematic as the animals could retreat a safe distance from one another. Staff at Scarborough Sea Life also admit that if the animals were housed in larger exhibits it would be “possible” that they could house more than one individual together .

The Giant pacific octopus and Mimic octopus, housed at Brighton Sea Life Aquarium, are likely to have been imported a great distance from the oceans to tank . During the investigation, staff at Brighton Sea Life told Freedom for Animals investigator that the Giant pacific octopus had been caught in the wild around a year and a half ago, when she was a month old.

The Mimic species is highly intelligent and can decide which predator to mimic to protect itself. In captivity however, the octopus displays none of these abilities. The display of this species has been questioned as there does not appear to be the wild population base required to support the intense collection of mimics and the pressure to acquire mimics is rapidly increasing. Their natural habitat is limited, as the coastal habitats in which they occur are some of the most heavily impacted in Indonesia, and yet easily accessible to collectors.

The Mimic octopus at Brighton Sea Life is housed in a restrictive, spherical tank no more than two foot in length. In captivity, these animals require a very deep, fine sand bed of around 10 inches to feel safe, however at Sea Life the animal is afforded only a thin layer of sand substrate and a child’s toy tube placed at the front of the tank, which the animal was hiding in. The Mimic octopus does not naturally live under rocks or in tubing. They have been demonstrated to live buried under sand for days at a time, which is possibly why  Sea Life does not provide the animal with a deep layer. Like other species of Octopus, the Mimic octopus is active late at night, and very early morning when light is the weakest. Another indicator that this animal is not suitable for an aquarium environment.

At Sea Life, Octopuses are provided with tubing, rope and children’s toys, such as Rubik cubes, ‘Mr. Potato Heads’, shape boxes, plastic telephones and plastic rocking horses. At Scarborough Sea Life, rocks, ceramic pots and netting serve as furnishings in the restrictive, traditional Common octopus tank.

There is a lack of appropriate theming in the majority of Octopus displays. At Brighton Sea Life, visitors were overheard questioning the children’s play room theme, as they didn’t understand it, and also comparing the Octopusus with young human children. Sea Life staff also inform visitors on talks and privately that the octopuses have the same intellect as two or three-year old children. Signage also states the same. This is hardly a fair comparison for the Octopus .

Sea Life staff claim: “We try and give them as much attention as we can and they seem happy”. Staff at Scarborough Sea Life told Freedom for Animals investigator that the female Common octopus could not be provided with a larger tank as the animal would feel “overwhelmed”. Staff stated: “In the wild, she would sit in a cave and wait” and “they don’t need a lot of space”. This is completely unfounded logic and staff also admit that a larger tank would mean visitors are less likely to easily view the animal.

At Weymouth Sea Life, the Octopus again is provided some netting, empty jars, pots and child toys. At Birmingham Sea Life, an octopus lives in a small spherical tank with an antique diving helmet for furnishing.

Octopus 2One of the most inappropriate environments afforded to Octopuses however is at Hunstanton Sea Life – a very small cylindrical tank with only a central column, a piece of tubing and two rocks in it. The animal has nowhere to retreat and, according to staff, has been living in this barren tank for over two years. Sea Life staff have put astro turf along the top of the tank closed as the animal kept escaping. At Manchester Sea Life also, a staff member admitted that the “Animal Care team have to pay special attention during feeding times ‘cos they do try to escape”.

The Octopus tanks at Sea Life are extremely restrictive, yet these animals are extremely intelligent, refuging predators who naturally live in dens and visit different areas each trip to hunt prey. They do not hunt in the same area each time since it would have been depleted by previous hunts. Spending their life in a completely predictable and unchanging acrylic/glass box is not only boring for them; it has a strong impact on both their health and behaviour. They have little cover apparently so visitors can view the animals, yet the more refuges there are, the more the animal would behave naturally.

Tanks are lit up yet, if given a choice, an octopus would probably choose little or no lighting for its environment. Most species of octopuses are nocturnal and even those who are active during the day prefer subdued lighting, rather than the intense lighting that your average reef tank provides. They are highly active predators who also have an unusually high metabolism for an invertebrate. This means that in practice that they usually have much more particular demands on some aspects of water quality than do most reef invertebrates.

Environmental enrichment is a common husbandry practice used to encourage natural behaviours and stimulate overall physical and psychological well-being. ‘Enrichment’ for octopuses at Sea Life includes puzzle boxes and screw lid jars, however an optimal environment would never need enrichment. Even if enrichment is added, this doesn’t change the fact that an animal’s space is too small.

Sea Life houses octopuses in cramped quarters which prevent normal natural movement. Additionally, the majority of octopus tanks at Sea Life are spherical in design, which increases the likelihood of visitors banging on the tank in an attempt to view the animals. At Manchester Sea Life, after opening only a few weeks, staff at the aquarium replaced an Octopus with another as the species is apparently “more active for visitors”. Hiding for all hours of the day is clearly viewed as undesirable. In fact, during the investigation none of these shy, nocturnal animals appeared active. Most were attempting to hide, albeit unsuccessfully.

Octopus brayThere are strong similarities and signs of continuity between vertebrate and invertebrate stress systems. In many invertebrates, molecules similar to adrenocorticotropin, one of the major stress-signalling molecules in vertebrates, have been found to be present. In captivity, these animals have special needs – they are very inquisitive and need ample hiding places to prevent stress. The environment and lifestyle of cephalopods means that they need to be capable of complex and flexible behaviours. As active predators they need to explore, understand and remember their environment and the behaviour of other animals.

Octopuses are known to exhibit abnormal behaviours in captive settings, particularly in sparse environments – irregular colour patterns, inking, and swimming or jetting into the tank walls are all considered signs of stress in an octopus. Octopuses have also performed autophagy, or the eating of their limbs.

This case study is an excerpt from the 2014 report An Investigation into the UK’s Largest Public Aquarium Chain.Please click HERE to access the full text (including references)

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