The suction pressure gauge of the Engine room bilge pump is broken and you don't have a spare. Chief Engineer has asked you to troubleshoot the problem with Bilge pump not taking suction from Fwd.(P) bilge well. You try taking suction from Fwd. (S) & Aft Bilge well and find that the pump is taking good suction. Thereafter you try suction from Fwd. (P) bilge well for sometime after priming with Sea Water but there is no change in level. You inspect the suction filter of the pump and find that it is very difficult to remove the same, you have to apply too much force to lift the filter cover while normally it comes out easily. What does it indicate?