Saturday 2 July 2022

Tabarca Island - Spain

Tabarca is an islet near Alicante on the Costa Blanca and is easily reachable from Santa Pola.  As it's been more than 6 months since I arrived in Spain, I was unable to rent a car with my UK licence (thanks Brexit) I therefore took the train down to Alicante from Valencia then the bus to Santa Pola. 

There are permanent inhabitats living on Tabarca all year round with numbers increasing significantly during the summer when tourism becomes the main economic activity.  It became a protected marine reserve in 1986 making it a very popular dive site.

 

Journey towards Tabarca

Dive 1: Islote de La Nao (#7 on map)


Islote de La Nao
Entry: 8:53am
Dive time: 52min
Depth: 9.9m
Temp: 27 degrees C
Weights: 8kg (overweighted 6kg better) 
Insulation: 3mm wet suit  

Met at the dive centre at 7:30 instead of 8:30 due to deterioration of weather forecast. It turned out to be very choppy.  Lots of people getting seasick.  I had planned to dive the next day at Tabarca but diving was cancelled and I decided against doing the shore dives at Cartagena.

Some nice arches which we were told not to swim through to protect sealife (it is a nature reserve)

 


Cratena peregrina



 
Juvenile damselfish, Chromis chromis

The brilliant blue colour of the juvenile damselfish, Chromis chromis, is common to rocky reefs ranging in depths from 3 to 35 m in the Mediterranean Sea.  It has been suggested that C. chromis is the most abundant fish species in the ecosystem and always ranked either number 1 or 2 in terms of most abundant species (Pinnegar, J.K.). It is a major prey item for larger fish and birds.

C. chromis feed in huge shoals and rest close to the seabed at night.  It consumes zooplankton and is a major consumer of fish eggs.  Shoals of adult damselfish fish can be seen here during a dive I did in Almeria.


The conditions made it difficult for some to enter the RIB
Choppy! 

Dive 2: Pecio 19 (#9 on map)

Entry: 10:35am
Dive time: 45min
Depth: 19.8m
Temp: 21 degrees C
Weights: 8kg (overweighted 6kg better) 
Insulation: 3mm wet suit  

 

 
 


Pinnegar, J.K. (2018) Why the damselfish Chromis chromis is a key species in the Mediterranean rocky littoral – a quantitative perspective

https://onlinelibrary.wiley.com/doi/10.1111/jfb.13551

Sunday 17 April 2022

"1ª Ensenada" and "2ª Ensenada", Dénia - Spain

Denia Port

Punta negra bay between Torre del Gerro on left and Montgó mountain

First dive of 2022.  Had hoped to do a good few more but weather wasn't great all week.  This subsequently affected the viz - not great so not many photos! Wore the 3mm for dives - Ok for first dive but a bit chilly at end of second. Dived with Mon Diving Centre.

 

1ª Ensenada

Entry: 10:10am
Dive time: 45min
Depth: 18.6m
Temp: 15 degrees C
Weights: 8kg (overweighted 6kg better)
Insulation: 3mm wet suit 

Journey out 
 



Highlight was a Moray eel between the crevices.

 2ª Ensenada

 
Entry: 11:33am
Dive time: 41min
Depth: 15.5m
Temp: 15 degrees C 
Weights: 8kg (overweighted 6kg better)
Insultaion: 3mm wet suit



 

Sea anemone (Anemonia sulcata)

Sea anemones can be a nice underwater watch.  They get their name from flowering plants but are actually predatory animals.  Sea anemones are a popular dish in Spain. It is known as ortiguillas, 'little nettles' or ortiga de mar, 'sea nettle'. To neutralize the poison, they are marinated in water with vinegar.

Anemones can reproduce either asexually or sexually, with each method offering distinct advantages and disadvantages. 

With asexual reproduction, the offspring are genetically identical to the original parent. Asexual reproduction allows for larger numbers of individual offspring to be produced more quickly with less energy expenditure as compared to sexual reproduction; in stable marine environments this is a reliable, efficient and effective means of reproduction. However, this lack of genetic diversity in offspring could collapse an entire population of genetically identical animals if environmental pressures were to swing too far from tolerable conditions. On the other hand, rapid rates of asexual reproduction allows for faster responses to environmental pressures as they are occurring and could raise the rate of survival if individual offspring develop genetic mutations during mitosis.

During sexual reproduction, sea anemones release genetic material (gametes) through the oral disk. With many species of sea anemones, genetic material from two or more distinct species are released into the water whereby sperm and egg will connect with the possibility of producing a genetically different and unique offspring from both parents. The genetic differences among multiple offspring increases the probability of survival.